Oasis science -5

Sound Energy
Sound is the form of energy which gives sensation of hearing to our ears. Sound energy
is produced by vibration. When sound waves strike our ear drum, we hear the sound.
Temple bell, drum, guitar, horn of vehicles, television, etc. are some sources of sound.
When these substances vibrate, sound is produced.

Fig. 10.5 Sources of sound

Activity 24

• Take a drum (Madal) and keep it as shown in the figure.
• Spread some chalk powder on the black part of the hide.
• Strike the edge of the hide with fingers and observe carefully.
• What happens to the chalk powder? What can you conclude

from this activity?
Fig. 10.6 Madal

Electrical Energy

Electrical energy is the most important source

of energy. It is required to light bulbs, to operate

radio, television, computer, to run industries,

etc. Electrical energy can be obtained from cell,

battery, rotating turbines, etc. The electricity that

we use at our homes is generated by rotating

turbines of generator with the help of running

water. The electricity generated with the help

of water is called hydroelectricity. We also obtain Fig. 10.7 Sources of Electricity
heat and light energy from electricity. We can

convert electrical energy into other forms of energy according to our needs. For example,

we use cells in torch light to obtain light energy. We use electric heater to convert

electrical energy into heat energy.

73 5Oasis School Science, Health and Physical Education Grade