1. A tennis ball on Mars, where the acceleration due to gravity is .379g and air resistance is negligible, is hit directly upward and returns to the same level 8.5 s later. (a) How high above its original point did the ball go? (b) How fast was it moving just after being hit? 2. v (y)= v (0y) + (a (y) * t) y=y (0) + v (0y)t + .5 a(y) t^2 v^2 (y)= v^2 (0y) + 2a(y) (y-y(0)) They're the equations of motion for constant acceleration 3. Well, the acceleration of gravity on Mars is 3.7 m/s^2. The answers are (a) 33.5 m, and (b) 15.8 m/s. I'm not sure how they got these answers, though. Any help would be greatly appreciated. Thanks!