Respond to the following questions by using the Dropdown
Boxes on the right to Select the best answers.
>>>>>>>>> ;>>>>>>>>&g t;>>>>>>>>& gt;>>>>>>>> >>>>>>>>> ;>>
travels as waves.

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?

If you put a helium-filled balloon in the refrigerator, what will happen?

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?