EVS Answer The Following question.

We need energy to run. Hence when we run a long distance, the food present in the body is continuously burn to release energy. This energy is used to do the work of running. After running a long distance the food gets exhausted and the energy released decreases and therefore we feel tired and we stop.

The energy has to be released from the fuel to make the car move. The energy is released when the petrol burns. The petrol starts burning only after we turn on the car engine. Since the engine is not on, the car does not move even when its tank is full of fuel.

Difference between substance and object is given below:

Substance	Object
1. Substances are made up of tiny particles.	1. Objects are made using substances.
2. Substances may or may not have definite shape. They occur in a specific state.	2. Objects have definite shape. Their parts are put together in a particular way.
3. Wood, aluminium, coal, iron etc are examples of substances.	3. Table, chair, flower pots, lamp etc. are examples of objects.

SELF

The raindrops slow down the roof and fall on the ground. They break into fine droplets when they fall and bounce off the ground. These droplets make us wet. Hence though the rain does not fall on us directly we get wet to some extent.

In a thermal power station coal is the original source of energy. Here coal is burnt to release heat. The heat generated is utilised to convert water to steam. Then steam is used to rotate the turbines. As the turbine rotates electricity is produced.

The capacity of a body to do work is called energy. Energy is obtained by burning fuel is in the form of heat. This heat is used to do work. The sources of energy are the sun, coal, diesel, CNG, LPG, petrol, wind, moving water and electricity

The differences in the solid, liquid and gaseous state of substances is given in the table below:

The naphthalene balls are continuously converted into small particles in the gaseous state. These particles settle down on the clothes in which they are kept. Therefore if naphthalene balls are kept for a long time in the clothes, they smell of naphthalene due to these particles.