12. A rock is thrown upward from the level ground in such a way that the maximum height of its flight is equal to its horizontal range d. (a) At what angle θ is the rock thrown? (b) What If? Would your answer to part (a) be different on a different planet? Explain. (c) What is the range dmax the rock can attain if it is launched at the same speed but at the optimal angle for maximum range?
