Page 1 - Lesson notes- heat
P. 1
SAI International School
Class 7
Lesson Notes
Subject: Physics
Ch-Heat and temperature
Subtopic: Heat
HEAT
Heat is the form of energy which gives sensation of hotness or coldness in a object.
S.I unit of heat is Joule (J).
Calorie is the other unit of heat.
1 calorie is the amount of heat energy required to raise the temperature of the 1 gram of
water through 1 C.
o
1 cal=4.2J
Heat always flows from high temperature to low temperature.
Effects of heat:
Ø Heat brings change in temperature.
Eg: Utensils on fire have high temperature.
Ø Heat can bring change in dimensions such as increasing the temperature causes
change in length, area and volume.
Ø Heat can change the state of substances.
