# Homework Help: Physics 12 Kinematics Question

1. Jul 4, 2008

### jameo15

1. The problem statement, all variables and given/known data
A ball rolls off the top of a 12.5m building with a speed of 3.4m/s. How long does it take to hit the ground? What is the range from the base of the building?

2. Relevant equations
V = V0 + at
Avg V = (V = V0) /2
d = V0 + 1/2 at2

3. The attempt at a solution
All I've got was a sketch drawn.. Please help me. Well I timed 12.5 by 3.4 to get how long it took to hit the ground but I'm not sure if it is right. I'm guessing to find the range you must need an angle of some sort?

Last edited: Jul 4, 2008
2. Jul 4, 2008

### Hootenanny

Staff Emeritus

Welcome to PF jameo15,

You need to consider the horizontal and vertical components of motion separately. When the ball rolls off the building, just at the point where it leaves the surface, what is it's vertical speed?

3. Jul 4, 2008

### jameo15

Would it's vertical speed be the acceleration due to gravity? But at the point where it leaves the surface, it should be zero right?

4. Jul 4, 2008

### Hootenanny

Staff Emeritus