At serve, a tennis player aims to hit the ball horizontally. If the player launches the ball from a height of 2.5 m and just clears a 0.90 m-high net about 15 m away as shown in figure below, determine
a. The initial speed of the ball?
b. The time of flight of the ball?
c. the range of the ball?
d. The speed of the ball and its direction of motion right before it hit the ground?