The state in which two bodies in physical contact with each other have reached identical temperatures is called:
1. Equalities of thermal temperature
2. conservation of temperature
3. thermal equilibrium

What is the speed of an object at a given moment?

How much energy must a refrigerator absorb from 225 g of water so that the temperature of the water will drop from 35°c to 5°c

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?