4.2 SPECIFIC HEAT CAPACITY

Selection building materials of traditional houses
in various climate – Cold climate

Materials for houses in cold climate :

WOOD

Reason:
Heat from fires lit in the wooden
houses cannot flow out because
wood functions as a good heat
insulator.

Production of latest materials
in the construction of green buildings

Materials of the roof:

Insulating concrete roof
(Roof fitted with insulators using
styrofoam board)

Reason:
Can reduce the absorption of heat
from surroundings to reduce the
temperature inside the building.
Because it has high specific heat
capacity

Outer layer of space capsules

Space capsule on its journey back to
Earth encounters air resistance when
entering the atmosphere.
This friction increases the temperature
and causes the space capsule to burn.

Material :
The outer layer of a space capsule
is made from substance with a high
specific heat capacity

Reason:
It heats up slowly and has high melting point
It will not melt at high temperature.

LEARNING
STANDARD 5

4.1.5 Solve problems involving
specific heat capacity
using formula, Q = mcθ

• Heat energy cannot be created.

• However, electrical energy, potential energy and
kinetic energy can be converted to heat energy.

Electrical energy heater Heat energy
Power = P Pt = mcө

Potential energy Object falls from Heat energy
a high position mgh = mcө

Kinetic energy Moving object Heat energy
stopped ½ mv2 = mcө

due to friction

Haba / heat :
Q = Pt = 1 000 x 5 x 60

= 300 000 J

Q = mcϴ
300 000 = (0.75)(4 200)ϴ
ϴ = 95.24⁰

Heat absorbed = heat released
0.2 x c x (ϴ- 40) = 0.8 x c x (100 - ϴ)
0.2ϴ - 8 = 80 - 0.8ϴ
ϴ = 80 + 8 = 88 ⁰C





Potential energy = heat
mgh = mcθ
→ 10 x 12 = 128 x ϴ

ϴ = 0.9375 ⁰C

THE END