Heat is the measure of average kinetic energy of particles within an object . It is the amount of thermal energy added to /removed from a system, and it can be transferred between systems. The unit that used to measure heat is calorie, which is the amount of energy it takes to increase the temperature of 1 gram of water by 1 degree Celsius. 1 calorie equals to 4.186 joules.
Heat transference sometimes happen between objects, but it could also happen within one object. Water, as an example, experiences convection when it gets heat up. Convection is the process when hot water gets to the surface while the cooler water sink to the bottom. Similar thing happen to gas/air as well.
Something intrigued me from today's learning is how people measure the energy that we absorb from food in the unit of Calorie. Is there any relationship between the energy from food and the energy that we apply to move our body? Why is 1 calorie defined as the amount of energy that takes to increase 1 gram of water by 1 degree Celsius? What is the difference between heat, thermal energy and temperature?
