In slow pitch softball, the pitcher pitches the ball to the batter in a high arc. suppose the ball leaves the pitchers hand when it is 2.5 feet above the ground with an upward velocity of 27 ft/s. the batter hits the ball when it is 3.5 feet above the ground. how much time elapses between the pitch and the hit? (meant to be a math question)

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?