# Stunt man jumping over cars

1. Jul 3, 2007

### heartofaragorn

1. The problem statement, all variables and given/known data
A stunt driver sets a jump off a horizontal platform and over ten cars. The height of the platform is 1.25 m, and the total distance of the cars is 20.0 m. Find the minimum speed required to safely clear the cars.

2. Relevant equations
x - x initial = velocity X t + 1/2 a t squared (??)

3. The attempt at a solution
I tried to follow an example from the book but got confused because of the height difference (the book example did not have a change in y). I looked at solving for various vector components, but I was unsure of the angle...if the driver is going off a flat surface, would the angle be 0? I figured that the change in y = -1.25 m and the change in x = 20.0 m, but after trying a few things, I kept getting stuck. Please help!

2. Jul 3, 2007

### Kurdt

Staff Emeritus
You have to set up two equations really. First you need to know how long it will take for the stunt rider to drop the 1.25 meters. Then you can work out how fast he needs to go to travel 20 meters horizontally in the time it takes for him to hit the ground again.

3. Jul 3, 2007

### heartofaragorn

Oh, thank you so much. I hate it when the answer is staring me in the face. I appreciate the help!