Heat L5 Class 7 Science Term 2 intro.pptx

Class 7 Heat

1. HEAT

2. Heat is a form of energy

3. Heat flows from a hot body to a cold body when they are kept in contact

4. We can define heat as follows Heat is a form of energy which flows from a hot body to a cold body when they are kept in contact. This process of heat transfer continues till the temperature of both the bodies becomes equal.

5. Sources of heat

6. Units of Heat The S.I. unit of heat is joule (J) The other common units of heat are calorie ( cal ) and kilocalorie (kcal)

7. One calorie: 1 g of water +1 C

8. Relationship between joule and calorie: 1 cal = 4.2 J (nearly) Or 1 J = 0.24 cal