# Initial Velocity of a Projectile

1. Oct 3, 2011

### AngeliaGW

1. The problem statement, all variables and given/known data

A ball is shot from a slingshot and clears a 10 meter fence 130 meters from the point of being flung and lands 10 meters behind the fence. What is the initial velocity of the ball? Assume the ball was caught at the same level it was kicked (delta Y=0).

2. Relevant equations

Delta Y=Voyt+1/2at^2
Delta Y=Vfy^2-Voy^2/at
Delta X=Voxt

3. The attempt at a solution

I'm unsure how to solve this problem as it involves multiple unknown variables. I think it involves 2 separate problems, one that is up to the fence and one that is after the fence. So 130=Voxt and 140=Voxt. For Delta Y, it would be Voy=4.9t. Please help :(

2. Oct 3, 2011

### AngeliaGW

Is it possible to assume that right when the ball passes the fence, that the initial velocity is 0 if I divide the problem into two? (One up to the fence, and one after the fence)

3. Oct 3, 2011

### SammyS

Staff Emeritus
No.

You can divide it in two, but the initial velocity for the second part should be the same as the final velocity from the first part.