- #1
jcruise322
- 36
- 1
Homework Statement
A sphere of radius .06 m and mass .5 kg rolls down a ramp that is angled 30 degrees down the incline. It starts rolling from a height of 7 feet and does not slip
What is its final linear velocity?
Now, I used mgh=translational +rotational KE and found that the final velocity was 9.9, but I didn't want to do that.
I wanted to use the formula acm=(g*sinθ)/(1+β) where β is the coefficient in front of mr^2 (for a sphere, .4 or 2/5).
So, Vf^2=vo^2+2*a*Δx.
My question is, which Δx do I use? I initially used the height and my answer was wrong...I was supposed to use the ramp, which by trig is 14 meters.
Homework Equations
acm=(g*sin(θ))/(1+β)
KE and PE equations.
V^2=Vo^2+2*a*Δx[/B]
The Attempt at a Solution
I already know the answer. I just want to know why the length of the ramp is used for v^2=vo^2+2adelta x equation.
Thanks, this should only take a moment. Appreciate any input guys! :) :)[/B]