Question

A tennis player stands 15.0m from the net. They hit a ball from a height of 2.50m above the ground so that initially it has a horizontal velocity directed parallel to the ground toward the net. What speed does the ball have to have to just clear the net (which is 0.9m high)? How long is the ball in the air and where does the ball hit the ground relative to the service line 7.0m from the far side of the net?