# Ball launcehd off a Cliff

1. Jan 28, 2010

### TheDoorsOfMe

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

Ok, you have a cliff with height h and you launch a ball off of it at speed v and angle $$\theta$$. How long till it hit the ground?

2. Relevant equations

(1) Vsin($$\theta$$) = V$$_{y}$$
(2) V$$_{f}$$ = V$$_{y}$$ + at
(3) d = ((V$$_{i}$$ + V$$_{f}$$)/2)*t

3. The attempt at a solution

Ok, so what I did was take equation (2) and set V$$_{f}$$= 0. This alllows me to solve for the time that it takes to reach peak. Multiply this result by 2 to get the time when the ball is back to the plane of the cliff. Then for the time down to the ground I used equation (3) and plugged in V$$_{f}$$= $$\sqrt{V^{2}_{i}+2gh}$$ for V$$_{f}$$. Then I solved for t.

This lead to a result I feel looked to complicated for the question. Did I do this right?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jan 28, 2010

### TheDoorsOfMe

Ok, I don't know why all my subscripts look like superscripts in this but they do. All those i's and f's are for intial and final velocity.