# Sphere rolling down a ramp

1. Jul 23, 2009

### iamtrojan3

1. The problem statement, all variables and given/known data
A solid sphere of uniform density (weight = 3.2 lbs starts from rest and rolls down a ramp (H = 1.57 m, q = 18.3°.)

Find the speed of the sphere's CM when it reaches the bottom of the ramp.

haha sorry bout that....

2. Relevant equations

see below

3. The attempt at a solution
i dont' know whats wrong with my set up here,
m*g*d*sin(theta) = .5mv^2 + (2/5)(.5)mv^2

any help?

thanks!

Last edited: Jul 23, 2009
2. Jul 23, 2009

### jgens

It might help if we knew what the question was!

3. Jul 23, 2009

### iamtrojan3

Ops... forgot to add the question. silly me >.<

4. Jul 23, 2009

### jgens

Your conservation of energy equation looks wonky. If I'm doing this right, you should have that m*g*h = (0.5)mv2 + (2/5)*(0.5)mv2. You're already given the height of the ramp!

5. Jul 23, 2009

### iamtrojan3

i hate when they put extra information in it, you just feel obligated to use it.

yes your right, thanks alot for the help!

6. Jul 23, 2009

### jgens

You're welcome! :)