PHYSICS [5 Mark Question Answer]

The different forms of energy are :
(i) Mechanical energy
(ii) Heat energy
(iii) Light energy
(iv) Chemical energy
(v) Sound energy
(vi) Magnetic energy
(vii) Electrical energy and
(viii) Atomic energy or nuclear energy.

The water in motion in a river or sea has the kinetic energy. The energy possessed by the flowing water is called the hydro energy. The most important use of hydro energy is to produce electricity from it.

Figure shows the principle of a hydroelectric power plant. The flowing water of the river is collected in a dam at a high altitude. The water stored in the dam has potential energy. When water from dam falls on the water turbine, the potential energy of the water stored in dam changes into its kinetic energy and this kinetic energy of water is transferred to the blades of turbine as the kinetic energy which rotates the turbine. As the turbine rotates, it rotates the armature of the generator (or dynamo) to produce electricity.

The example to show the conversion of potential energy to kinetic energy when put in use is :
A stone at a height has the potential energy due to its lifted or raised position. In the figure below when the stone is dropped from that position, it begins to fall. The falling stone has the kinetic energy. Thus, the potential energy stored in the stone in its raised position changes into the kinetic energy when the stone is falling. This kinetic energy does work on the nail as the stone strikes the nail arid makes the nail to move into the wood.

Similarly, in the figure below the potential energy possessed by the stone at a height changes into its kinetic energy when it falls, The kinetic energy of the falling stone does work in raising the weight upwards.

Match the following columns

COLUMN A	COLUMN B
1. Running water	1. kinetic energy
2. Burning	2. heat energy
3.Energy	3.joule
4.Sound energy	4. vibrations
5.Nuclear energy	5. atom bomb