Question 1: What is heat? What is the S. I. unit of heat?
Answer: Heat is a form of energy, which when absorbed by a body makes it hot and when extracted from a makes it cold. It is also defined as the total kinetic energy possessed by all the molecules of a body. The S. I. unit of heat is joule/kg kelvin.
Question 2: Define the term calorie. How is it related with joule (the SI unit of heat)?
Answer: One calorie is the heat required to raise the temperature of 1 g of water from 14.5°C to 15.5°C
1 Calorie = 4.2 joule.
Read more about specific heat of water