I will help with this one and you try the others. If you get stuck, write back. I doubt if you respond back at all anyway, but here goes. You did not specify units, so I will use feet.

Originally Posted by
pilar22
A tennis player hits a ball at ground level, giving it an initial velocity of 28.0 at 52.0 above the horizontal.
What are the horizontal and vertical components of the ball's initial velocity?
Horizontal component:
Vertical component:
How high above the ground does the ball go?
The max height is achieved when dy/dx=0
Solve for t and we get
Plug this into y and get 7.61 feet
How long does it take the ball to reach its maximum height?
As showed before, 69 sec.
What is the ball's velocity at its highest point?
The velocity is 0 at the highest point.
For how long a time is the ball in the air?
Set it equal to 0 and solve the y component for t. You get two values. The good one is 1.38 seconds
When this ball lands on the court, how far is it from the place where it was hit?
Plug the previous answer into the x component and get 23.77 feet