- #1
johnhuntsman
- 76
- 0
A thin solid disk of radius R = 0.5 m and mass M = 2.0 kg is rolling without slipping on a horizontal surface with a linear speed v = 5.0 m/s. The disk now rolls without slipping up an inclined plane that is at an angle of 60 degrees to the vertical. Calculate the maximum height that the disk rolls up the incline.
The disk will stop when kinetic energy K equals the work done by gravity Wg.
R = 0.5m
M = 2.0kg
v = 5.0m / s
θ = 60°
I = (1 / 2)MR2
ω = v / R
K = (1 / 2)Iω2 + (1 / 2)Mv2
Wg = mgh = mgdcosθ
The fact the θ to the vertical is given suggests that I'm meant to find h using it, but it seems to me that I wouldn't actually need it. However solving for h that way doesn't get me the right answer which makes me think I need to use it somehow. Can someone please help?
P.S. The correct answer is 2.6m.
The disk will stop when kinetic energy K equals the work done by gravity Wg.
R = 0.5m
M = 2.0kg
v = 5.0m / s
θ = 60°
I = (1 / 2)MR2
ω = v / R
K = (1 / 2)Iω2 + (1 / 2)Mv2
Wg = mgh = mgdcosθ
The fact the θ to the vertical is given suggests that I'm meant to find h using it, but it seems to me that I wouldn't actually need it. However solving for h that way doesn't get me the right answer which makes me think I need to use it somehow. Can someone please help?
P.S. The correct answer is 2.6m.