# Tennis question

1. Jan 3, 2010

### vertex78

Trying to get my head around the velocity vector that a tennis ball goes after it is hit with a tennis racket. To make matter easier, I am only thinking about it in terms as if the ball is sitting in midair motionless when the racket hits it.

Say the ball is hit with a force of 1N and the mass of the ball is 0.057kg then the acceleration is 1N/0.057kg. Is this enough information to calculate the trajectory of the tennis ball?

Even though the ball height verses distance is in one plane, determining what angle that plane is in relative to where the player is standing confuses me as well. I have a feeling I an just conceptualizing things wrong.

(And no this is in no way related to a homework question)

2. Jan 3, 2010

### diazona

If you know the force, you would also need to know the time over which that force is applied. The longer the force is applied, the faster the ball will be going at the end. The product (actually integral) of force and time is called impulse, and it does provide enough information to calculate the final velocity of the tennis ball.

3. Jan 4, 2010

### Marshall10488

you would need to know the vector forces of which the ball was hit, time of acceleration and then the path would be the negative acceleration due to drag in the x and then acceleation due to gravity in the y assuming you are only lookin at x and y and not considering a cross wind which would then give you a z component.
just a thought, since my mind is currently on this, would there be any lift forces involved either from the shape of the ball or its rotation?