Energy is measured in joules (j). which other quantity is measured in joules?
a. work
b. force
c. power
d. acceleration

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?

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.

1700 j of energy is lost from 0.14 kg object , the temperature decreases from 50°c to 45°c what is the specific heat of this object, amd what is the material ?