PL AR RS P6L13 Energy Forms, Uses & Conversions WS

Primary 6

Rocket Science

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ENERGY FORMSE,NUESREGSYAFNODRCMOSN, UVESERSSIAONNDS (CLOESNSVOENRS1I3O)NS (LESSON 13)

Primary 6: Rocket Science

Lesson Outline

• Notes
• Activity 1: Hands-on Activity
• Activity 2: MCQs
• Activity 3: Open-ended Questions
• Activity 4: Fun Facts

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Primary 6: Rocket Science

Energy Forms, Uses and Conversions – NOTES

Forms of Energy Light energy Electrical energy
Heat energy

Forms of Energy

Kinetic energy Sound energy

Potential energy

Chemical potential Gravitational Elastic potential
energy potential energy energy

Energy can be stored, used and changed from one form into another. Energy cannot be created
or destroyed.

Kinetic Energy

• Kinetic energy is the energy that moving objects have. For example, wind is moving air. Wind
has kinetic energy.

• The amount of kinetic energy an object has depends on the mass and the speed of the moving
object.

• Objects with more mass have more kinetic energy. For example, if a bus and a car are moving at
the same speed, the bus has more kinetic energy than the car.

• The faster an object moves, the more kinetic energy it has. For example, if two identical cars are
moving at different speeds, the car that is moving faster has more kinetic energy.

• An object at rest has no kinetic energy. For example, a stationary car has no kinetic energy.

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Primary 6: Rocket Science

Energy Forms, Uses and Conversions – NOTES

Light Energy
• Light energy is the form of energy that allows us to see. Objects can be seen if they give off

light or if then reflect light.
o Objects that give off light are sources of light, e.g. a torch, burning wood, a gas flame,
the Sun.
o The Moon is not a source of light. It can be seen because it reflects light from the Sun.

Heat Energy
AR Model – Flashlight

• Heat energy is the form of energy that can cause an object to change its temperature or
state.

• Besides producing heat by various natural heat sources (the Sun and burning fuels) or
from electrical appliances, heat energy can also be produced by moving or rubbing things
together.

Sound Energy
• Sound is a form of energy that we can hear. It is produced by vibrating objects.
• Sound travels outwards from the object producing it towards our ears. Sound needs a medium

(e.g. solid, liquid, gas) to travel through, or else it cannot be heard.
o For example, sound cannot travel in a vacuum.
• There are many types of sound. We usually use sound energy to communicate.
o Music is a type of sound which is pleasant to listen to and has a regular pattern.
o Noise is a type of sound which is unpleasant to listen and has an irregular pattern.

Electrical Energy
• Electrical energy or electricity can be changed to other forms of energy, such as light, sound

and heat energy, and is the most widely used.

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Primary 6: Rocket Science

Energy Forms, Uses and Conversions – NOTES

Potential Energy
•Potential energy is also known as stored energy. It can be used and changed into other forms of
energy.
•Some forms of potential energy include, chemical energy, gravitational potential energy and elastic

potential energy.

•Chemical Potential Energy
Chemical potential energy is stored in any kind of food, fuel or battery.
The stored energy can be released as usable energy. For example,
Food – Respiration
Fuel – Burning
Battery – In closed electric circuit

•Gravitational Potential Energy

Any object that is above the ground, hanging from something or on top of a slope has
gravitational potential energy.
The amount of gravitational potential energy an object has depends on its
mass and its height from the ground.
Objects with more mass have more potential energy. If two different balls are at the same
height above the ground, the ball with more mass will have more gravitational potential
energy.
The higher an object is from the ground, the more potential energy it has. If two identical
balls (same mass) are at different heights above the ground, the ball that is higher up will
have more gravitational potential energy.

•Elastic Potential Energy
A form of potential energy which is stored in rubber bands, stretched springs and

compressed springs.

AR Model –Spring

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Primary 6: Rocket Science

Energy Forms, Uses and Conversions – NOTES

Energy changes
Remember: Energy cannot be created or destroyed. It can only change from one form to

another.
• During photosynthesis

Light energy (from the Sun)  Chemical potential energy (Stored as food in the plant)
• When a battery is used in a close electric circuit with a bulb

Chemical potential energy (Stored in the battery) Electrical energy (carried by current in
the circuit)  Light energy (given off by the bulb) + Heat energy (given off by the bulb)
• During respiration
Chemical potential energy (from food)  Heat energy (warms the body) + Kinetic energy
(when we move) + Other usable energy (used in other life processes)
• When a ball falls from a height
Gravitational potential energy Kinetic energy
• In power stations
Gravitational potential energy (of stored water)  Kinetic energy (of moving water) 
Kinetic energy (of turbine)  Electrical energy

• In fuel-burning power stations
Chemical potential energy (of fuels)  Heat energy  Kinetic energy (of steam)  Kinetic
energy (of turbine) Electrical energy

Bulb

Battery

A fuel-burning power station

Hydroelectric power station Switch

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Primary 6: Rocket Science

Activity 1 – Hands-on Activity: Rubber band energy
Objective: To observe relationship between kinetic energy and potential energy.
Materials: Rubber band, a paper cup sliced in half lengthwise, a ruler
Procedure:
1. Stretch the rubber band to three different lengths – short stretch, medium stretch, and

long stretch. Each length of the rubber band is a “condition” of the experiment.
2. Conduct 3 trials for each condition.
3. For the 3 trials for each condition, make sure the rubber band is stretched exactly the

same length and that the cup starts in the exact same place.
4. Carefully aim the rubber band at the same spot on the cup (so the cup will move in the

same direction).
5. Record how far the cup moves for each trial. Then calculate the mean distance for each

of the 3 conditions.

Discussion questions:
1. What is the energy conversion from the hand to the cup moving?
2. Will it be a softer or louder sound from the cup when the rubber band is

stretched further?

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Primary 6: Rocket Science

Activity 2 – MCQs

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Primary 6: Rocket Science

1. An engineer wanted to find out how the design of wind turbines affects the amount of
electricity generated. He used 3 different wind turbines as shown below.

AR Model –Wind Turbine 10m 5m
5m

Blade

DesignA Design B Design

He fitted the 3 designs to 3 similar generators and placed them in tChe same field. A few

days later, he recorded his observations in the table below.

Design Length of blade (m) Number of blades Electricity generated
(units)
A5 3 3000
B 10 3 14000
C5 6 5000

What can he conclude from the results above?

A: More blades generate more electricity.
B: Fewer blades generate more electricity.
C: Longer blades generate more electricity.
D: Shorter blades generate more electricity.

(1) A and C only
(2) A and D only
(3) B and C only
(4) B and D only

()

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Primary 6: Rocket Science

2. Which of the following most accurately shows the energy conversion of a battery-
powered torch?

torch )
(1) electrical energy light energy  heat energy
(2) chemical potential energy  light energy  heat energy
(3) electrical energy  chemical potential energy  light energy+ heat energy
(4) chemical potential energy  electrical energy  light energy + heat energy

(

3. The picture below shows some solar panels found on the roof of a water treatment plant.

AR Model –Solar Panel

Solar panel

AR Model –
Solar Panel

The solar panels use energy from the Sun to power the lights in the water treatment
plant.

Which of the following correctly shows the energy conversion that allows the lights in the
water treatment plant to be powered using the Sun?

(1) light energy  light energy + heat energy
(2) electrical energy light energy + heat energy
(3) heat energy  electrical energy  light energy + heat energy
(4) light energy  electrical energy  light energy + heat energy

()

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Primary 6: Rocket Science

4. Boris skateboarded on the ramp as shown in the diagram below. He started at Point A
and moved down the ramp towards Point D.

A

BD ()

C
Which point does Boris have the greatest kinetic energy?

(1) A
(2) B
(3) C
(4) D

5. A wooden hammer tied to a string was released. It swung and hit the plastic bottle. The
bottle fell.
string

hammer

plastic bottle

Which of the following shows the correct energy conversion?
(1) Kinetic energy of hammer  potential energy of the hammer  kinetic energy of the

bottle
(2) Potential energy of hammer kinetic energy of the hammer  kinetic energy of the

bottle
(3) Potential energy of hammer kinetic energy of the bottle  potential energy of the

bottle
(4) Kinetic energy of hammer  potential energy of the bottle  kinetic energy of the

bottle
()

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Primary 6: Rocket Science

6. Irene placed a ball at position G on a table. The ball rolled to position H, rolled down the
table and landed at position K. It then continued to roll till it came to a stop at position L,
as shown below.

GH

table top

floor ()
KL

Which of the following statements are correct?.

A: The kinetic energy of the ball decreases from K to L.
B: The ball has kinetic energy and potential energy at H.
c: The potential energy of the ball increases from H to K.
D: The potential energy of the ball increases from H to K.

(1) A and B only
(2) A and C only
(3) B and D only
(4) C and D only

7. The table below shows how far a wound-up toy train can move when the key is given a
different number of turns each time.

Number of turns 1 2 4 6 8 10
Distance moved (cm) 5 10 20 30 40 50

If Jeremy wants the toy train to move a distance of 44cm, what is the least number of
turns that he needs to make?

(1) 6 turns
(2) 7 turns

(3) 8 turns
(4) 9 turns

()

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Primary 6: Rocket Science

8. Tony and Mark, with the same mass, were descending from X and Y of a tall tower
respectively to land at Z as shown in the diagram below. The ropes used at X and Y
were the same.

X

Tony

Y
Tower
Z Mark

Who will reach Point Z first and why? )

(1) Mark as his position is closer to Point Z than Tony.
(2) Tony as he has greater potential energy than Mark.
(3) Tony as he is heavier than Mark and has more potential energy.
(4) Mark as he gains more kinetic energy than Tony since he is at a lower position.

(

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Primary 6: Rocket Science

9. The diagram shows how the spring inside the kitchen scale works when measuring the
mass of an object.

when nothing is placed on the when an object is placed
kitchen scale on the kitchen scale

Length of
spring

Mrs Ong used the kitchen scale to measure the mass of four objects, A, B, C and D. She
measured and recorded the length of the spring when each object was placed on the
kitchen scale.

Object A B CD
Length of spring (cm) 15 7 4 12

Which object caused the spring to possess the greatest amount of elastic potential )
energy when it was placed on the kitchen scale?

(1) Object A
(2) Object B
(3) Object C
(4) Object D

(

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Primary 6: Rocket Science

10. Jane hung 3 metal balls, J, K and L, one at a time, from a string and released each one
from either position X or Y.

ceiling string X metal ball
bell Y

The table below shows the mass of each metal ball and the position from which each ball
was released.

Metal Ball Mass of metal ball (g) Position released from
J 200 X
K 100 Y
L 200 Y

Using a datalogger, she recorded the sound level when the metal balls hit the bell in the
table below.

Which of the following shows the likely sound level recorded for each metal ball? (Sound
is measured in decibels or db. A high decibel reading means a loud sound has been
detected.)

Metal Ball J (db) Metal Ball K (db) Metal Ball L (db)

(1) 100 100 150

(2) 150 100 150

(3) 250 100 150

(4) 250 150 100

()

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Primary 6: Rocket Science

Activity 3 – Open-ended Questions
1. Ian carried out an experiment using a metal ball.

Ball 2cm
1cm

Dent

He dropped the ball from a height of 50 cm onto a container of sand. The ball created a
circular dent which was 2 cm in diameter and 1 cm deep.

(a) Ian dropped the metal ball from different heights. State how the depth of the dent

would change with the height of each drop. [1]

(b) Write down the energy changes as the metal ball is dropped from a height of [1]
50 cm.

Gravitational energy energy energy
potential (in falling ball)
(in ball as it drops into the sand)
energy

(in ball held above
sand)

(c) People may be injured when they are hit by objects thrown out from the high floor

of a tall building. Give a reason for this. [1]

_________________________________________________________________

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Primary 6: Rocket Science
2. Darren made a rubber band toy car as shown below.

Wooden stick Cardboard
Rubber band

Wheel

He turned the wheels to roll the rubber band around the wooden stick 10 times at
position P and placed his toy car on the table. The toy car moved forward across the table.

(a) State the energy conversion that takes place from the time he released the toy

car on the table until it comes to a stop. [2]

energy energy
of the rubber band of the toy car

+

energy
+

energy

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Primary 6: Rocket Science

(b) Without changing the set-up of the toy, suggest a way Darren can make his toy

car move further. [1 ]

Darren wanted to find out if the number of turns of the rubber band affects the distance
travelled by the toy car. He placed the toy car first on a wooden table, then on a plastic
table during his experiment. However, his brother told him that his experiment was not
fair.

(c) Explain why Darren’s experiment was not fair. [1]

(d) Besides the one that is mentioned in (c), list another variable that has to be kept

the same in the experiment for it to be a fair test. [1]

________________________________________________________________

________________________________________________________________

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Primary 6: Rocket Science
Activity 4 – Fun Facts: Carbon dioxide as the future of fuel

https://www.youtube.com/watch?v=Mb_8DJF6Hp0
Discussion Questions:
1. What reacts with carbon dioxide to produce the fuel?
2. How does this technology help save the environment?

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