Draw the velocity versus time graph for a ball that is thrown up into the air. draw the graph only until the ball reaches the top, right before it starts to come back down. assume there is no air resistance. be sure to label your axes with the correct values

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?