- #1
cortozld
- 11
- 0
Homework Statement
A solid ball is at the top of a 2 meter inclined plane. Assuming friction is negligible, what is its linear speed (m/s) as it reaches the bottom?
Homework Equations
PE=mgh
KE=.5mv^2
RKE=.5Iw^2
I of ball=.4mr^2
w=v/r
The Attempt at a Solution
Pretty much what i did was set PE=KE+RKE
which is mgh=.5mv^2+.5(.4mr^2)+w^2 masses cancel out and so does r when v/r is replaced with w
equation is now gh=.5v^2+.5(.4)v^2
if i solve for v i get: 2v^2=2gh/.4= v^2=gh/.4
thus v=sqrt(9.81*2/.4)
v=7.0 m/s
i really have no idea if I am doing this right...