A2 kg picture frame sits on a shelf at a height of 0.5 m. how much gravitational potential energy is added to the picture frame when it is lifted to a shelf of height 1.3 m? acceleration due to gravity is g = 9.8 m/s2.

a.10.23 j b.15.68 j c.25.48 j d.9.80 j

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?