CONTENTFORCE AND MOTION II Resultant Force Resolution of Force Forces in Equilibrium Elasticity PRESSURE Pressure in Liquids Atmospheric Pressure Gas Pressure Pascal’s Principle Archimedes’ Principle Bernoulli’s Principle ELECTRICITY Current and Potential Difference Resistance Electromotive Force (e.m.f.) and Internal Resistance Electrical Energy and Power ELECTROMAGNETISM Force on Current-carrying Conductor in a Magnetic Field Electromagnetic Induction Transformer ELECTRONICS Electron Semiconductor Diode Transistor NUCLEAR PHYSICS Radioactive Decay Nuclear Energy QUANTUM PHYSICS Quantum Theory of Light Photoelectric Effect Einstein’s Photoelectric Effect DEFINITION LIST Form 4 Form 5 2 7 10 12 18 24 28 31 33 40 44 51 65 68 74 78 84 90 96 100 106 111 116 121 123 127 129
FORCE AND MOTION I HEAT 1 = + 1 = 2 = ! " ( + ) 2 = 3 = + ! " " 3 = 4 " = " + 2 4 !! = "" 5 Momentum = 5 #! $! = #" $" 6 = 6 %! $! = %" $" GRAVITATION WAVES 1 = &'!'" (" 1 = 2 = &' (" 2 = )* + 3 = '," ( 4 = ," ( 5 = "-( $ LIGHT AND OPTICS 6 $! " $" " = (! # ("# 1 = . , 7 = 8&/ ( 2 = 012 3 012 ( 8 = − &'!'" ( 3 = ! 012 . 9 = 8"&/ ( 4 = 4 5 5 ! 6= ! , + ! 7 6 ! sin ! = ! sin " 7 Linear magnification, = , 7 SPM | Physics
FORCE AND MOTION II ELECTRONICS 1 = 3 = ! " " 1 Electrical potential energy, = 2 = ! " 2 Maximum kinetic energy, = ! " " 3 = 8$ 8% PRESSURE 1 = 9 : NUCLEAR PHYSICS 2 = ℎ 1 = F ! " G ; < 3 = ' , 2 = " 3 = 3.00 × 10= m s>! 4 1 a. m. u. = 1.66 × 10>"?kg GRAVITATION 1 = 9 @ 6 = + QUANTUM PHYSICS 2 = @ A 7 = 1 = ℎ 3 = B @ 8 = B A 2 = . C 4 = 9 = # D 3 = 5 E 5 = FG : 4 = 5 ', 5 = 5. C 6 = ℎ ELECTROMAGNETISM 7 ℎ = + ! " " ')* 8 = ℎ< 1 #& #' = H& H' 9 = 9.81 m s>" @ 9.81 N kg>! 2 = IJKLJK LNOPQ R2LJK LNOPQ × 100% 10 = 6.67 × 10>!! N m" kg>" 11 ℎ = 6.63 × 10>STJ s SPM | Physics
“UNLEASH THE POWER OF FORCE, LET MOTION BE YOUR GUIDE!” FORCE AND MOTION II 1S P M P H Y S I C S
Definition: The single force that represents the vector sum of two or more forces acting on an object. RESULTANT FORCE Two forces acting in the same direction Two forces acting in opposite direction Two forces acting perpendicular to each other Two forces acting on an object in the directions that are not perpendicular to each other 2 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
Resultant Force on an Object in Various States of Motion § If the resultant force acting on the object is equal to zero, = 0, the object is said to be in equilibrium. § Newton’s Second Law of Motion is applied to describe the situation. = RESULTANT FORCE ON AN OBJECT IN VARIOUS STATES OF MOTION Object in stationary Velocity, = Acceleration, = Resultant force, $%& = Object moving with a uniform velocity Velocity, = Acceleration, = Resultant force, $%& = Object moving with a uniform acceleration Velocity, = Acceleration, = Resultant force, $%& = ✏ CHECKPOINT A model car moves forward as shown below. What is the acceleration of the model car? 3 Physics CHAPTER 1 FORCE AND MOTION II
EXAM WATCH Diagram shows a lorry at rest. ', (, ) and * are the forces acting on the lorry. Which equation shows the correct relationship of forces when the lorry starts moving forward? A ' < ( and ) = * B ) < * and ' = ( C ' > ( and ) = * D ) > * and ' = ( Diagram shows two forces, and . Which diagram shows the resultant force of and ? A C B D MRSM 2022 Question 25 Pahang 2022 Question 22 Elevator system § When we are standing on a weighing machine, the reading on the weighing machine is equal to the reaction force. ELEVATOR SYSTEM SITUATION EXPLANATION REMARK Lift at rest or moving up or down at a constant velocity Lift moves up at an acceleration of m s-2 Lift moves down at an acceleration of m s-2 4 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
✏ CHECKPOINT 1 What is the apparent weight of a girl on a weighing scale in a lift of the cable of the lift suddenly breaks? 2 A woman of mass 50 kg is standing in a lift. Determine the magnitude of the normal reaction when the lift is a) stationary b) moving upwards with acceleration of 1.5 m s-2 c) moving with uniform velocity of 9.2 m s -1 EXAM WATCH Diagram shows a student stands on a weighing scale. He experienced three different elevator motion situation X, Y and Z. What is the following equations is true about apparent weight, ? X Y Z A = = − = + B = − = = + C = = + = − D = + = − = Kelantan MPSM 2022 Question 22 5 Physics CHAPTER 1 FORCE AND MOTION II
Pulley system § A pulley consists of a wheel and a rope. It is used to lift heavy objects to a height. § When we pull at the ends of the string, the tension produced has the same magnitude along its entire length. ✏ CHECKPOINT 1 A 2 kg weight is connected by a rope to a 3 kg wooden block. The rope passes over a smooth pulley as shown in the diagram. The weight is then released. Find the tension in the rope if a friction of 5 N acts against the wooden block. [Using = 10 N kg-1] 2 Two masses of 5 kg and 3 kg are connected to a rope which passes over a frictionless pulley. Find the tension in the rope and the acceleration of the 3 kg mass when the 5 kg mass is released. EXAM WATCH Diagram shows X and Y connected by a string over a smooth pulley. When the system is released, X and Y accelerates at 4 m s-2. What is the friction force between X and the table surface? A 1.00 N B 5.00 N C 6.50 N D 9.43 N Melaka 2021 Question 22 6 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
Definition: Resolution of forces is the process of resolving a force into two components. ✏ CHECKPOINT 1 A boy is pulling a toy car with a force of 6 N as shown in the diagram. If the toy car is moving with a constant velocity, what is the friction against the toy car? 2 A gardener pushes a 250 kg concrete roller with force of 200 N directed from the handle. The handle is at an angle of 33° to the horizontal. What is the total downward force on the ground? 7 PhysicsCHAPTER 1 FORCE AND MOTION II
3 Ali and Abu are pulling a trolley on which their sister, Tina is sitting. Both Ali and Abu pull the rope with a force of 50 N, which makes an angle of 30° with the direction of motion. The total mass of Tina and the trolley is 30 kg and the friction between the trolley and the floor is 40 N. Find the acceleration of Tina and the trolley. EXAM WATCH Diagram shows a lawnmower used by a gardener to cut grass. The lawnmower is less efficient when used. You are required to give some suggestion of modification and reasons so that the lawnmower more stable and can be used efficiently based on aspects such as way to move the lawnmower, angle of θ, size of cutter blade, mass of the lawnmower and the length of handle. [10] Method of moving: Reason: Size of angle, : Reason: Size of cutter blade: Reason: Mass of lawnmower: Reason: Length of handle: Reason: 8 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
Inclined plane INCLINED PLANE SMOOTH ROUGH ✏ CHECKPOINT 1 A carton of mass 5 kg is at rest on an inclined plane making an angle of 15° with the horizontal. Find the frictional force and the normal reaction force acting on the carton. 2 Diagram shows a horizontal force, acting on a wooden block of weight 8 N placed on a smooth plane at 30° to the horizontal. What must the magnitude of be to prevent the block from sliding down? 9 PhysicsCHAPTER 1 FORCE AND MOTION II
Object is said to be in equilibrium if the resultant force acting on it is equal to zero. ✏ CHECKPOINT 1 Sketch the triangle of forces. 2 Diagram shows the tension, T in a wire supporting a picture frame of weight, W = 250 N. a. Draw the triangle of forces for the weight of the picture frame and the tensions in the wire acting on the picture frame. b. Calculate the magnitude of T. 10 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
3 Joan and her sister lift a pail of water of total mass 5.6 kg. Each of them exerts a force of at 25° to the vertical. Find the magnitude of . 4 A lamp of weight 25 N is supported by two ropes as shown in the diagram. Given that the tension in rope A is 20 N, find the angle and the tension in rope B. EXAM WATCH Which statement is correct when an object is in equilibrium of forces? A The object is either stationary or moving with a uniform velocity. B The object moves with a uniform velocity. C The object becomes stationary. D The object is either moving with uniform velocity or with a uniform acceleration. Diagram shows a flower pot of mass 2 kg hanging from a pole. Calculate the tension, of each string. A 11.54 N B 20.00 N C 23.09 N D 40.00 N Negeri Sembilan 2022 Question 21 Johor 2021 Question 21 11 Physics CHAPTER 1 FORCE AND MOTION II
Definition: Elasticity is the property of material that enables an object to return to its original shape and size after the force applied on it is removed. Forces between Atoms The atoms in a solid are arranged in an orderly and packed manner. The atoms have constant distance between each other. FORCES BETWEEN ATOM COMPRESSED EQUILIBRIUM STRETCHED Hooke’s Law Definition: Hooke’s law states that the extension of a spring is directly proportional to the force applied on the spring provided the elastic limit of the spring is not exceeded = Analysis of the Graph of Force Against the Extension of a Spring = applied force = spring constant = extension of spring Elastic Potential energy, + = work done to stretch the spring = (average force) × extension of spring = ,-. (× = ' ( Based on graph of against : Area under the graph = Area of right-angle triangle = ' (× × = ' ( Elastic Potential energy, + = Area under the graph = ' ( = ' (( 12 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
EXPERIMENT 1.1 Inference: Extension of the spring depends on force. Hypothesis: Force increases, extension of the spring increases. Aim: To investigate the relationship between force and extension of the spring. Variables: a) Manipulated: Force, b) Responding: Extension of the spring, c) Constant: Stiffness of the spring Apparatus and Materials: spring, slotted weight, metre rule, retort stand with clamp, pin, plasticine, thread Arrangement of Apparatus: Procedure: 1 Stiffness of spring is fixed. The original length of the spring, ! is determined. Slotted weight of mass, = 50 g is hung at the lower end of the spring. 2 The extended length of the spring, is determined and recorded. 3 Repeat the experiment with = 100 g, 150 g, 200 g and 250 g. Results: Mass, / g Mass, / kg Force, / N Length, / cm Extension, / cm 50 0.050 100 0.100 150 0.150 200 0.200 250 0.250 Data Analysis: A graph of against is plotted. Conclusion: Extension of the spring, is directly proportional to / increase linearly with the force, / cm / N 13 Physics CHAPTER 1 FORCE AND MOTION II
FACTORS AFFECTING THE VALUE OF SPRING CONSTANT, FACTOR SPRING CONSTANT GRAPH OF AGAINST Material of spring Steel spring > copper spring Length of spring Short spring > long spring Diameter of spring Small diameter > large diameter Thickness of spring wire Thicker wire spring > thinner wire spring ARRANGEMENT OF SPRING SERIES PARALLEL The stretched force applied on the system of spring acts on each spring. The stretching force applied on the system of spring is divided equally among the springs. Extension of system of springs = + = 2 Extension of system of springs = " # Spring constant of spring system = $ # Spring constant of spring system = + = 2 14 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
ARRANGEMENT OF SPRING Extension of the spring system: Spring constant of the spring system: Extension of the spring system: Spring constant of the spring system: Extension of the spring system: Spring constant of the spring system: Extension of the spring system: Spring constant of the spring system: ✏ CHECKPOINT 1 The original length of a spring is 16 cm. When a load of mass of 100 g is suspended at the end of the spring, the length of the spring becomes 20 cm. a) What is the spring constant of the spring? b) How much load is needed to extend the spring to length of 22 cm? 2 Diagram shows a system of 6 identical springs. The original length of each spring is 12 cm and extends to 15 cm with a load of 200 g. What is the length y of the spring system? 15 Physics CHAPTER 1 FORCE AND MOTION II
3 A spring with a 300 g sphere attached to it is extended by 5 cm. The force constant of the spring is 200 N m-1. What is the elastic potential energy stored in the spring? What is the maximum velocity of the sphere when the stretching force is released? EXAM WATCH Diagram shows a load of 1 kg is hung by three arrangement of identical spring. Which comparison is correct about the extension of the spring for arrangement P, Q and R? A Q < P < R B P < Q < R C R < P < Q D R < Q < P Diagram shows a graph of force, against extension. of two springs, P and Q. Which statement is correct? A Spring constant of Q is greater than spring constant of P. B Spring Q is stiffer than spring P. C Spring P is made of steel while spring Q is made of copper. D The elastic potential energy of spring Q is higher than spring P. SBP Model Paper Set 2 Question 22 SBP Model Paper Set 3 Question 21 Diagram shows a spring of suspension system of a motor. By using the knowledge of elasticity, suggest characteristics of spring which enable it to absorb shock efficiently. Explain your suggestion based on the following aspects such as material of the spring, physical condition of the spring, spring constant and rate of damping of the spring. [10] Material of spring: Reason: Length of spring: Reason: Diameter of spring: Reason: Diameter of wire: Reason: Spring constant: Reason: Rate of damping: Reason: 16 Physics Force and Mo+on II Pressure Electricity Electromagne2sm Electronics Nuclear Physics Quantum Physics
"THE INVISIBLE FORCE THAT SHAPES OUR WORLD, PUSHING BOUNDARIES AND SPARKING CHANGE." PRESSURE 2S P M P H Y S I C S
Pressure Definition: Force per unit area = = ℎ S.I unit: Pascal (Pa) // N m-2 ✏ CHECKPOINT Figure shows a submarine travelling from the surface of the sea to a depth of 6000 m. If the density of sea water is 1025 kg m-3, calculate the pressure exerted by the sea water on the submarine at that depth. = force = surface area = pressure in liquid ℎ = depth in liquid = density of liquid = gravitational acceleration 18 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
EXPERIMENT 2.1 Inference: Pressure in a liquid depends on depth in the liquid. Hypothesis: Depth in a liquid increases, pressure in the liquid increases. Aim: To investigate the relationship between depth in a liquid and pressure in the liquid. Variables: a) Manipulated: Depth in the liquid, ℎ b) Responding: Pressure in the liquid, represented by the difference in heights of the water columns, in the U-tube c) Constant: Density of the liquid, Apparatus and Materials: 500 m measuring cylinder, silicone tube, thistle funnel with its mouth closed by a thin sheet of rubber, U-tube, metre rule, retort stand, water and food colouring Arrangement of Apparatus: Procedure: 1 Density of the liquid is fixed. The thistle funnel is outside the measuring cylinder and the water level for both arms of U-tube are the same. The thistle funnel is immersed into the measuring cylinder until the depth, ℎ = 4.0 cm. 2 The difference in heights of water columns, between the two water levels in the U-tube is determined. 3 Repeat the experiment with ℎ = 8.0 cm, 12.0 cm, 16.0 cm and 20.0 cm. Results: Depth of water, ℎ / cm Difference in heights of water columns, / cm 4.0 8.0 12.0 16.0 20.0 Data Analysis: A graph of against ℎ is plotted. Conclusion: Difference in heights of water columns, is directly proportional to / increase linearly with depth in water, Water pressure is directly proportional to / increase linearly with depth in water, / cm ℎ / cm 19 PhysicsCHAPTER 2 PRESSURE
EXPERIMENT 2.2 Inference: Pressure in a liquid depends on density of the liquid. Hypothesis: Density of the liquid increases, pressure in the liquid increases. Aim: To investigate the relationship between density of a liquid and pressure in the liquid. Variables: a) Manipulated: Density of the liquid, b) Responding: Pressure in the liquid, represented by the difference in heights of the water columns, in the U-tube c) Constant: Depth of the liquid Apparatus and Materials: metre rule, beaker, U-tube, silicone tube, thistle funnel with its mouth covered by a thin sheet of rubber, retort stand, masking tape, water, alcohol and glycerine Arrangement of Apparatus: Procedure: 1 Depth of liquid is fixed at 2 cm from the base. The mouth of the thistle funnel is brought near to the surface of the alcohol and is immersed into the level fixed. 2 The difference in heights of water columns, between the two water levels in the U-tube is determined. 3 Repeat the experiment with water and glycerine. Results: Type of liquid Density of liquid, / kg m-3 Difference in heights of water columns, / cm Alcohol 4.0 Water 8.0 Glycerine 12.0 Data Analysis: A graph of against is plotted. Conclusion: Difference in heights of water columns, is directly proportional to / increase linearly with density of liquid, Liquid pressure is directly proportional to / increase linearly with density of the liquid, / cm / kg m-3 20 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
CHARACTERISTICS OF PRESSURE IN A LIQUID THE PRESSURE IN A LIQUID INCREASE WITH DEPTH THE PRESSURE IN A LIQUID ACT IN ALL DIRECTIONS THE PRESSURE IN A LIQUID DOES NOT DEPEND ON THE AREA OF ITS SURFACE THE PRESSURE IN A LIQUID DOES NOT DEPEND ON THE SHAPE OF SIZE OF THE CONTAINER THE PRESSURE AT TWO POINTS AT THE SAME LEVEL IN THE SAME LIQUID ARE EQUAL Determine the density of an unknown liquid by using U-tube Liquid pressure at point A, ! = ℎ !! , where ! = density of liquid X Liquid pressure at point B, " = ℎ "" , where " = density of liquid Y Since points X and Yare at the same level and both liquids are static, pressure at point A = pressure at point B ! = " ℎ !! = ℎ "" ℎ !! = ℎ "" ✏ CHECKPOINT A U - tube is filled with water and cooking oil as shown in the figure. Density of water is 1000 kg m-3. Calculate the density of cooking oil. 21 PhysicsCHAPTER 2 PRESSURE
1 The pressure exerted by a liquid at depth, h is = ℎ. 2 The surface of the liquid experienced by an object in a liquid is calculated with the following formula, Actual pressure = ℎ + #$% ✏ CHECKPOINT A fish at a depth of 2.5 m in the sea. The density of sea water is 1050 kg m-3 while the atmospheric pressure is 100kPa. [Gravitational acceleration, g = 9.81 m s-2] a) Calculate the pressure experienced by the gold fish due to the water around it? b) Then, determine the actual pressure acting on the fish. APPLICATION OF PRESSURE IN LIQUIDS POSITION OF WATER TANK AT A HOUSE § Water tank is placed at high position to produce high pressure § Water flows out at high speed CONSTRUCTION OF A DAM § The wall is built thicker at the base of the dam to withstand high water pressure § The penstock is at lower section § High water pressure will produce a fast flow of water to drive the turbine POSITIONING OF INTRAVENOUS LIQUID BAG § The bag of intravenous liquid is placed at position higher than body § Pressure produced push the intravenous liquid into the body § Rate of flow of intravenous liquid depends on the height of the bag or controlled by adjuster 22 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
USE OF SIPHON § A siphon is used to transfer liquid from a higher region to a lower region § The siphon tube is fully filled with water. One end of the tube is placed in the tank of water at the higher position while the other end is placed at the lower region § The flow of water from end C produces a region of lower pressure at B. Atmospheric pressure pushes the water into tube at A ✏ CHECKPOINT 1 A diver dives to a depth of m in the sea where he experiences a total pressure of 2 atmospheres. What is the depth of the diver in the sea? [1 atmosphere = 105 Pa, density of seawater, = 1060 kg m-3 and gravitational acceleration, = 9.81 m s-2] 2 Figure shows the supply of water to a condominium from a reservoir. a) Why the wall of the dam is being built thicker toward the base of the dam? b) What is the pressure in pascal at point P? [density of water = 1000 kg m-3] 23 PhysicsCHAPTER 2 PRESSURE
Definition: Atmospheric pressure is the pressure due to the weight of the layer of air acting on the surface of the Earth. 1 Atmospheric pressure acts on every object on the surface of the Earth. 2 At sea level, the atmospheric pressure is about 1.013 × 105 N m-2. This value is referred to as 1 atmosphere. 3 Meteorologists express pressure in millibars. One millibar is 100 N m-2 or 100 Pa. Hence, 1 atmosphere is about 1013 millibars. 4 The atmospheric pressure decreases slowly with altitude because the atmosphere becomes thinner at higher altitude. To Show the Existence of Atmospheric Pressure Activity Physics Bytes It is difficult to pour milk out from a tin with one hole. However, when an additional hole is made, milk can be easily poured out. Why? Solution § When milk is poured out, pressure in tin decreases. § Higher atmospheric pressure acts against milk. § When an additional hole is made, atmospheric air fills the space in the tin, thus balancing the pressure. § Milk flows out easily as there is no external pressure against it. Mercury Barometer 1 A mercury barometer is used to measure the value of atmospheric pressure. 2 A mercury barometer is a one meter long glass tube containing mercury. 24 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
Since the atmospheric pressure at the sea level can support a vertical column of mercury 76 cm or 760 mm high, we can, for convince, use mm Hg as a unit of pressure. 1 atm = 76 cm Hg = 760 mm Hg In unit of N m-2 or Pa 1 atm = 76 cm Hg = ℎ = = In unit of m H2O What is the height of a water column that one atmosphere can support? TYPE OF BAROMETERS FORTIN BAROMETER ANEROID BAROMETER The value of atmospheric pressure is determined by the height of mercury column The value of the atmospheric pressure is determined by the volume of the partial-vacuum metal box. Larger size and not portable Smaller size and portable Takes longer time to give a reading for atmospheric pressure Gives a direct reading for atmospheric pressure. 25 Physics CHAPTER 2 PRESSURE
EXAM WATCH Diagram shows a Fortin barometer to be used to measure the atmospheric pressure Barometer Pointer material Bag material Protecting tube material Extra measuring instrument W Ivory Paper Glass Hydrometer X Ivory Leather Brass Thermometer Y Iron Leather Glass Thermometer Z Iron Paper Brass Hydrometer You are required to investigate the characteristics of the barometers to be used in Fortin barometer in the diagram above. Explain the suitability of each characteristic of the barometers. Determine the most effective barometer to be used to measure the atmospheric pressure. Give reasons for your choice. [10] Aspect Reason Terengganu 2022 Question 10 ✏ CHECKPOINT 1 Sometimes it is more convenient to use mm Hg and m H2O as unit for pressure. Thimphu is a town in the country of Bhutan which is located at a very high altitude. If the weather forecast states that the atmospheric pressure in Thimphu is 520 mm Hg, what is the value in pascal? 2 A dam is able to withstand a maximum water pressure of 1.55 × 106 Pa. Find the maximum pressure in unit m H2O. [Density of H2O, = 1.00 × 103 kg m-3 and gravitational acceleration, = 9.81 m s-2] 26 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
✏ CHECKPOINT 1 Figure shows a simple barometer standing vertically on a table in a laboratory. [Density of mercury = 13.6 × 103 kg m-3 ; = 9.81 m s-2] a) What is the value of atmospheric pressure in the laboratory in i. cm Hg ii. Pa b) If the tube is pushed 10 cm downwards, what is the length of the column of mercury in the tube? Explain your answer. EFFECT OF ATMOSPHERIC PRESSURE TYPE OF PRESSURE ATMOSPHERIC PRESSURE AT HIGH ALTITUDE PRESSURE AT AN EXTREME DEPTH UNDER THE SURFACE OF THE SEA STATE § Thinning of air causes the atmospheric pressure to become lower § The percentage of oxygen in the air decreases. § Water pressure increases with depth § An increase in depth of 10 m causes an increase in water pressure by 1 atm § Water pressure and atmospheric pressure are experienced EFFECT ON HUMAN BEINGS § Increase in the rate of breathing § Lower absorption of oxygen in the lungs § Increase in the metabolic rate § Loss of appetite § Dehydration § Inability to think clearly § Body tissues absorb excess nitrogen gas § Nitrogen gas dissolves into the blood § Inability to think clearly § Formation of nitrogen bubbles in the tissues or blood vessels if pressure is reduced too rapidly ADAPTION AND ACTION TO BE TAKEN Mountain Climbers § Prepare and train before climbing § Prepare equipment such as smartwatch, that can measure altitude, blood pressure and body temperature § Climb at a slower rate to allow the body to adjust to the changes in pressure § Drink water even when not thirsty to prevent dehydration Aircraft § Increase the pressure in the aircraft cabin to match the sea level pressure § Recycle the air in the cabin so that it is fresh and contains adequate oxygen level Remind passengers to drink enough water to prevent dehydration during long distance flights Divers § Do physical exercises to enable the body to adapt to a high pressure environment before diving § Wear a diving suit to slow down heat loss from the body § Slowly ascend to sea level so that nitrogen bubbles do not form in the tissues and blood vessels Submarines § The submarine hull is made of steel or titanium with a circular cross section withstand high surroundings pressure § Pressure in the cabin of the submarine is controlled to almost the same as at the sea level for the comfort of crew § Oxygen tanks or electrolytic oxygen generators are provided so that oxygen supply is adequate 27 PhysicsCHAPTER 2 PRESSURE
2 Figure shows an arrangement of apparatus that can be used to measure atmospheric pressure. It is known that the atmospheric pressure at sea level is 76 cm Hg. [Density of mercury = 13.6 × 103 kg m-3 ; g = 9.81 m s-2] a) If the apparatus is brought to sea level, what is the value of h? b) What is the pressure at the point X in pascal? c) What will happen if this apparatus is brought to the Moon? Explain your answer. Manometer Pressure at A = gas pressure, Pgas Pressure at B = pressure due to water column, h + atmospheric pressure = h cm H2O + Patm Point A and point B are at the same level, therefore Pressure at A = Pressure at B Pgas = h cm H2O + Patm 28 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
Bourdon Gauge § Measure gas pressure in the unit of pascal, Pa ✏ CHECKPOINT 1 A mercury manometer is attached to a gas supply. The gas pressure of the gas causes a difference of level of mercury as shown in the diagram. The difference in the level is 38 cm. What is the pressure of the gas in a) cm Hg b) pascal [Patm = 76 cm Hg or 105 Pa] 2 Figure shows a manometer used to measure the gas pressure in a flask when the temperature increases. When h is 12 cm, what is the gas pressure in pascal? [Patm = 76 cm Hg; density of merucry = 13.6 × 103 kg m-3; density of liquid X = 2.5 × 103 kg m-3; g = 9.81 m s-2] 29 PhysicsCHAPTER 2 PRESSURE
3 Figure shows a water manometer connected to nitrogen cylinder. The reading of a mercury barometer is 750 mm Hg. a) Calculate the nitrogen pressure in pascal. [Density of mercury = 13600 kg m-3, g = 9.81 m s-2] b) Predict what will happens to the water column in the manometer when the valve of the nitrogen cylinder is opened. Explain your answer. 4 A mercury manometer is used to measure the pressure in an air flow pipe. a) State the difference between the air pressure in the pipe and the atmospheric pressure in cm Hg. b) If atmospheric pressure is 75 cm Hg, what is the air pressure in the pipe in Pa? [Density of Hg, = 13 600 kg m-3, gravitational acceleration, = 9.81 m s-1] EXAM WATCH Diagram shows a manometer being connected to a container filled with gas. What happens to the height of water, h if the piston is pushed downwards? A Increase B Decrease C No change Diagram shows a manometer that is used to determine the pressure of gas in a container. Which statement is correct? A The gas pressure is equal to 15 cm Hg. B The gas pressure is equal to the atmospheric pressure. C The gas pressure is less than the atmospheric pressure. D The gas pressure is higher than the atmospheric pressure. MRSM 2023 Question 29 SBP 2023 Question 30 30 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
Pascal’s principle states that the pressure applied on an enclosed fluid is transmitted uniformly in all directions in the fluid. HYDRAULIC SYSTEM AS FORCE MULTIPLIER WORKING PRINCIPLE 1 Input force, ! is applied on the input piston 2 High pressure is produced at the input piston 3 Pressure is transmitted uniformly in the hydraulic fluid to the output piston 4 Large output force, " is produced at the output piston CHARACTERISTICS OF HYDRAULIC FLUIDS § High boiling point – does not evaporate easily § Does not form bubbles in hydraulic system – pressure transmitted uniformly § Low rusting effect – pipe does not rust easily § Low density – hydraulic fluid can flow smoothly in the pipes Pressure on the liquid surface below the input piston, ! = &! '! Pressure on the liquid surface below the input piston, " = &" '" Since pressure is transmitted uniformly, " = ! &" '" = &! '! APPLICATION OF PASCAL’S PRINCIPLE HYDRAULIC BRAKE SYSTEM HYDRAULIC JACK 1 Driver exerts force on the brake pedal. 2 Force acts on small piston and high pressure is produced. 3 Pressure is transmitted uniformly in the hydraulic fluid. 4 Large force is produced at the large piston. 5 Large piston pushed the brake pad and the brake disc is pressed. 1 When handle is pushed, force applied at the small piston. 2 High pressure is produced. 3 Pressured is transmitted uniformly in the hydraulic fluid. 4 Large force is produce at the large piston and load is lifted. 31 Physics CHAPTER 2 PRESSURE
✏ CHECKPOINT 1 In the hydraulic system shown in the diagram, an input force of 10 N is used to balance an output force, F2. Calculate F2. 2 Diagram shows an activity to demonstrate the hydraulic system as a force multiplier. A small boy uses a force of 8 N to press the piston of the small syringe with a cross-sectional area of 1.6 cm2. His elder brother presses the piston of the large syringe with a cross-sectional area of 64 cm2. What is the minimum force that the elder brother needs to apply so that the piston of the syringe will not be forced backward? 3 A victim was trapped under a collapsed wall after an earthquake. A portable hydraulic pump is used to lift the collapsed wall, as shown in the diagram, in order to save the victim. The cross-sectional area of the input piston is 15 cm2. If the ratio of the input force to the output force is 3 : 80, calculate the crosssectional area of the output piston. 32 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
EXAM WATCH Diagram shows an excavator used a hydraulic system to unload sand from the excavator bucket in a construction area. Hydraulic system Type of fluid The rate of boiling of hydraulic fluid The cross-sectional area of master piston The crosssectional area of slave piston R Water Low Big Small S Water High Big Small T Oil High Small Big U Oil Low Small Big Study the specifications of all the four hydraulic systems. Explain the suitability of each specification of the hydraulic systems and determine the most suitable hydraulic system to be used to unload sand from the excavator bucket. Give reasons for your choice. [10] Aspect Reason Kelantan MPSM 2021 Question 10 Diagram shows a chair for a dental treatment. Explain how this chair can be lifted up. [4] Melaka 2022 Question 11 Buoyant Force, FB Definition: Buoyant force is the force acting upwards on an object immersed in a liquid when there is pressure difference between the lower surface and upper surface of the object. 33 PhysicsCHAPTER 2 PRESSURE
Buoyant force = Actual weight – Apparent weight ✏ CHECKPOINT 1 The weight of a stone in air is 0.65 N. When it is completely submerged in water, its weight is 0.50 N. What is the buoyant force acting on the stone when it is completely submerged in water? 2 Diagram shows an empty oil drum floating on the surface of a pond. Label the two forces acting on the oil drum. Archimedes’ principle states that an object which is partially or fully immersed in a fluid will experience a buoyant force equal to the weight of fluid displaced. buoyant force = weight of fluid displaced ( = RELATIONSHIP BETWEEN THE EQUILIBRIUM OF FORCES AND THE STATES OF FLOATATION OF AN OBJECT IN A FLUID = # > # < # Resultant force = 0 Resultant force downwards Resultant force upwards Balanced forces Unbalanced forces Unbalanced forces Object is stationary Object moves downwards with acceleration, a Object moves upwards with acceleration, a 34 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
APPLICATION OF ARCHIMEDES’S PRINCIPLE HYDROMETER § Measure relative density of liquid § Used at milk manufacturing factories to test the dilution of milk. SUBMARINE HOT AIR BALLOON § The burner heats up the air inside the balloon § Hot air is less dense than air outside the balloon § Balloon rises ( weight < buoyant force) § Burner is turned off and hot air is released. § Balloon comes down (weight > buoyant force) SHIP AND PLIMSOLL LINE § Weight of the ship = Buoyant force = Weight of water displaced § The Plimsoll line marked at the side of the ship indicates the maximum depth to which the ship may be immersed to sail safely in the sea § The Plimsoll line is also a guide about the maximum weight of the load that be carried by the ship in water of different densities CARTESIAN DIVER § When the diver is placed in a bottle of water, some air remains trapped in the holes. § If the cork at the top of the bottle is pressed downwards, the pressure in the water increases. Some water is forced into the holes of the diver, compressing the air in them. The weight of the diver increases and it sinks. § When the pressure is released, the compressed air in the holes pushes the water out. The weight of the diver decreases and it rises. § The working principle is same as the submarine. Buoyant force = weight Submarine is floating Water enters the ballast tank of submarine Weight > buoyant force Submarine dives into the sea Compressed air forces water out of the ballast tank Weight < buoyant force Submarine rises 35 PhysicsCHAPTER 2 PRESSURE
✏ CHECKPOINT 1 A block with a volume of 0.06 m3 is floating on the surface of water with ) * of its volume submerged. What is the buoyant force acting on the block? [density of water = 1000 kg m-3] 2 A concrete slab weights 150 N. When it is fully submerged under the sea, its apparent weight is 102 N. Calculate the density of the sea water if the volume of the sea water displaced by the concrete slab is 4800 cm3. [ = 9.81 N kg-1] 3 Figure shows a helium filled balloon with a volume of 0.06 m3 floating stationary in the air. The density of air and helium are 1.3 kg m-3 and 0.18 kg m-3 respectively. a) What is the weight of the helium in the balloon? b) Calculate the buoyant force of acting on the balloon. c) What is the weight of W required to make the balloon stationary in the air? (Ignore the weight if the material of the balloon) 4 A fishing boat sails from sea into a river. Figures (a) and (b) show when it is on the sea and on the river respectively. From the figure, compare a) the buoyant forces acting on the boat b) the weights of the sea water and the river water displaced by the boat c) the densities of the sea water and the river water 36 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
5 Figure shows a boat loaded with some goods floating on the sea. The density of the sea is 1020 kg m-3. a) Calculate the weight of the boat. b) Figure below shows the situation of maximum loading of the boat. Calculate the additional weight of goods that must be added to the boat to reach this situation. 6 A lump of clay of volume 50 cm3 has been shaped to displace 400 cm3 when wholly immersed in water. Will the shaped clay float or sink in water? [Density of clay, +,#- = 1600 kg m-3, density of water, .#$/0 = 1000 kg m-3 and gravitational acceleration, = 9.81 m s-2] 37 PhysicsCHAPTER 2 PRESSURE
EXPERIMENT 2.3 Inference: Buoyant force depends on weight of water displaced. Hypothesis: Weight of water displaced increases, buoyant force increases. Aim: To investigate the relationship between weight of water displaced and buoyant force. Variables: a) Manipulated: Weight of water displaced, $ b) Responding: Buoyant force, % c) Constant: Density of water, Apparatus and Materials: Slotted weights, Eureka can, beaker, spring balance, electronic balance, retort stand, wooden block and water Arrangement of Apparatus: Procedure: 1 Density of water is fixed. Slotted weight of mass, = 100 g is hung on the spring balance and the weight of slotted weight in the air, & is recorded. The slotted weight is fully immersed into the water and weight of slotted weight in water, ' is recorded. Weight of water displaced is recorded. 2 Buoyant force, % = &− ' is calculated. 3 Repeat the experiment with = 200 g, 300 g, 400 g and 500 g. Results: Weight in the air, & / N Weight in water, ' / N Weight of water displaced, $ / N Buoyant force, % = &− ' / N 1.0 2.0 3.0 4.0 5.0 Data Analysis: A graph of $ against % is plotted. Conclusion: The buoyant force, % is directly proportional to the weight of water displaced, $. The buoyant force, % is equal to the weight of water displaced, $. $ / N % / N 38 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
EXAM WATCH Diagram shows three toys P, Q and R are floating in a bath tub. Which of the following is true about the buoyant force acting on toys P, Q and R? A Q = R = P B Q > P > R C R > P > Q D P > R > Q Diagram shows the displacement of water after a solid iron ball is completely immersed in an Eureka can. If the volume of iron ball is 50 cm3, what is the weight of water displaced? [density of water, = 1000 kg m-3] A 0.4905 N C 4905 N B 49.05 N D 490500 N MRSM 2023 Question 31 Kelantan MPSM 2022 Question 24 Diagram below shows a hot air balloon in an annual festival during Historical Malacca City Day. Based on the diagram, suggest a modification on the hot air balloon so that the balloon will float higher based on the following aspects: [4] The temperature of the hot air balloon: Reason: Size of the balloon: Reason: SBP Model Paper Set 2 Question 7 Table shows the characteristics of four structures of ship P, Q, R and S. Structure of ships Shape Strength of the metal used Ship base crosssectional area Volume of the air space in the ship P Streamlined High Wide High Q Oval Low Wide High R Circle High Small Low S Streamlined Low Small Low As a researcher in a ship manufacturing company, you are assigned to study the structure used to make the ship to support heavy cargoes. You are given four choices of the structures P, Q, R and S. The table above shows the structures of the ship. Explain the suitable characteristics of the structure to be used to make the ship. Determine the most suitable structure to be used to make the ship to support heavy cargoes. Give reasons for your choice. [10] Aspect Reason Melaka 2021 Question 10 39 Physics CHAPTER 2 PRESSURE
Bernoulli’s principle states that when the velocity of a fluid increases, the pressure in the fluid decreases and vice versa. Observation Based on Bernoulli’s Principle LIFT FORCE EFFECT OF LIFT FORCE ON A PING PONG BALL § Air flowing at a high velocity above the ping pong ball produce a region of low pressure. § Difference between the pressure produces a resultant force upwards § Resultant force is the lift force that lifts up the ping pong ball PRODUCTION OF LIFT FORCE BY THE AEROFOIL § Aerofoil shape of the wing causes air to flow at different velocities. § According to Bernoulli’s principle, higher velocity at the top section produces a region of lower pressure while lower velocity at the bottom section produces a region of higher pressure. § These differences of pressure produce a resultant force acting upwards. § When the aerofoil is at a certain angle of attack, the aerofoil exerts a force on the air flow. § When an air stream hits the lower part of the aerofoil at an angle known as angle of attack, it is deflected downwards. According to Newton’s Third Law, a reaction force with equal magnitude but opposite direction acts on the aerofoil. This force will contribute to the upward lift. 40 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
APPLICATION OF BERNOULLI’S PRINCIPLE RACING CAR (INVERTED AEROFOIL) 1 At top region, air flow with low speed creates region of high pressure. 2 At lower region, air flow with high speed creates region of low pressure. 3 Different in pressure produces a downward force. HYDROFOIL 1 Use the same principle as aerofoil. 2 When boat moves, water above the foil moves faster than the water below it. 3 Different in pressure produces a lift force. 4 At certain speed, when the lift produced is equal to the weight, the hull rises above the surface of water. 5 This results in a great reduction in drag and a corresponding increase in speed. BUNSEN BURNER 1 Butane gas flows with high speed. 2 Low pressure region is formed. 3 Surrounding air flows in and mixes with butane gas. 4 Blue flame is produced. CURVED BALL 1 The direction of the spin of the ball is the same as direction of the air. 2 Speed of air increases produce a lower pressure region. 3 Difference in pressure produces force. 4 Force acting on the ball changes the direction of the ball. INSECTICIDE SPRAYER 1 When the plunger is pushed in, air flows out at high velocity. 2 Low pressure region above metal tube. 3 Higher atmospheric pressure acts on the liquid insecticide. 41 Physics CHAPTER 2 PRESSURE
EXAM WATCH Diagram shows the roof of a house being lifted during a storm. Which statement is correct to explain the phenomenon? A Speed of air at Q is lower causing lower air pressure B Speed of air at Q is higher causing higher air pressure C Speed of air at P is higher causing lower air pressure D Speed of air at P is lower causing lower air pressure. Which of the following diagrams shows the correct water level in tubes T, U, V and W? A B C D SBP Model Paper Set 4 Question 23 SBP Model Paper Set 1 Question 24 Diagram below shows a cross section of an aeroplane wing. The wing helps the aeroplane to be lifted up when the plane speeding along the runway. Name the shape in the diagram and explain how the aeroplane can be lifted up into the ai. [4] Perlis MPSM 2021 Question 11 Diagram shows the cross-section of the wings of the airplane. Suggest the methods and modifications that need to be done on the wings of the plane for the plane to begin to take off from the runway based on the following aspects. Give a reason for your answer. [6] Angle of attack: Reason: Area of wing: Reason: Density of wing material: Reason: SMKA dan SABK 2022 Question 8 42 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
"THE SILENT SPARK IGNITING INNOVATION AND LIGHTING UP OUR WORLD WITH ENDLESS POSSIBILITIES." ELECTRICITY 3S P M P H Y S I C S
Electric Charge There are two types of electric charge: § Positive charge, Proton (+), +1.6 × 10!"# C § Negative charge, Electron (−), −1.6 × 10!"# C Electric Field Definition: A region where electrical charges experience electric force. 1 Electric field is usually represented by arrow lines. These arrow lines are called electric field lines or electric lines of force. 2 The direction of the arrowed lines indicates the charge of the object. a) For positive charges, the electric field is usually represented by arrow lines pointing out of the object. b) For negative charges, the electric field is usually represented by arrow lines pointing inwards. 3 Electric field lines are not intersected each other. Physics Bytes Like charges repel and unlike charges attract ELECTRIC FIELD PATTERN UNLIKE CHARGES LIKE CHARGES PARALLEL CHARGED PLATES CHARGED PARTICLE AND CHARGED PLATE H T TIPS 1 The electric field between two opposite charged metal plates is called a uniform electric field. This is because the electric field lines are parallel and equally spaced. 2 Electric field lines are from the positive plate to the negative plate. 3 The electric field strength increases when the potential difference between the plates increases or the distance between the plates decreases. 44 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics
✏ CHECKPOINT Sketch the electric field lines for the following arrangement of charges. Electric Field Strength, E Definition: Force acting on a unit positive charge placed in the electric field. ELECTRIC FIELD STRENGTH POINT CHARGE PARALLEL CHARGED PLATE = S.I. unit: N C-1 = S.I. unit: V m-1 1 Electric field is stronger if the two charges are closer to one another. 2 For diagrammatic representation, the electric field strength can be determined by the density of the electric field lines. 3 For stronger electric field, the electric field lines are denser and arranged more closely to one another. Physics Bytes § A petrol tanker will be positively charged due to air friction. § Sparks may be produced and causes fire. § Metal chains are connected from the tank to the ground for the charges to flow to the ground. = electric field strength = potential difference = distance between two parallel plates = electric field strength = electric force = electric charge 45 PhysicsCHAPTER 3 ELECTRICITY
✏ CHECKPOINT 1 A 2 C charge is placed in an electric field with the strength of 1.6 N C-1. What is the electric force acting on the charge? 2 When a test charge of 0.25 μC is placed in an electric field, it experiences a force of 0.18 N acting on it. Calculate the strength of the electric field experienced by the electric charge. 3 Two similar metal plates are mounted parallel and perpendicular to the insulator at 20 cm apart as shown in the diagram. The two plates are then charged at a voltage of 400 V from E.H.T. voltage supply. a) What is the electric field strength between the two parallel plates? b) A test charge of −0.02 mC is placed at the centre point of the two plates. i. What is the electric force acted on the test charge? ii. State the direction of the force. 46 Physics Force and Mo+on II Pressure Electricity Electromagne+sm Electronics Nuclear Physics Quantum Physics