Sphere rolling down a ramp problem

[iamtrojan3]

Homework Statement

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...

Homework Equations

see below

The Attempt at a Solution

i dont' know what's wrong with my set up here,
m*g*d*sin(theta) = .5mv^2 + (2/5)(.5)mv^2

any help?

thanks!

 

[jgens]

It might help if we knew what the question was!

 

[iamtrojan3]

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

 

[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!

 

[iamtrojan3]

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

yes your right, thanks a lot for the help!

 

[jgens]

You're welcome! :)