Page 80 - ScienceStd4

3. Take a thin dry stick.

4. Rub the stick on a piece of dry wood.

5. Touch the part of the rubbed stick and write down your
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observation.

There are various sources of heat, such as the sun, electricity,

burning wood and friction. Additionally, some forms of energy
can be converted into heat energy. For example, sunlight can
be converted into heat energy, electrical energy and chemical
energy. Rubbing two objects together also generates friction,

which produces heat energy, as observed in Activity 1.

Heat transfer

Heat energy can travel from a hot source to a cooler area. It
can move through solids, fluids (liquids and gases) and empty

space or vacuum space.

Experiment 1: Investigating transfer of heat through solid
objects

Aim: To demonstrate the transfer of heat through solid
objects

Materials: A piece of metal or a spoke, a piece of wood, heat

source such as a stove, matchstick and wax or a
candle

Caution: Be careful when using fire to avoid fire related
hazards.

Procedure

1. Lay the piece of metal on top of the piece of wood as
shown in Figure 2(a).

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