# Projectile motion

1. Feb 25, 2010

### Physuph

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

"A quarterback standing at his own 10.0 yard line throws the football to a receiver at the moment the receiver crosses the (nearer) 30.0 yard line. Knowing that the receiver runs with a velocity of 8.0 m/s, and the quarterback threw the football at an angle of 30 degrees, and that the pass was complete, what was the velocity with which the ball was thrown? (1yard= .01m).

2. Relevant equations

3. The attempt at a solution

First, I drew myself a diagram..
delta x = Vox *t= (30-10)*t + 8.0*t
T=2Vo sin 30deg / 9.8 = Vo/9.8

I don't know if i have to get into component vectors, and use pythagorean theorem, or what not. I have no clue how to solve this...

2. Feb 25, 2010

### Sirsh

Well, I'd say you'd have to find out the amount of time it takes the reciever to catch the ball first.

3. Feb 25, 2010

### Physuph

I've tried doing that. I just ended up with a bunch of equations with t and Vo and I when I put them together I just go in circles.