A small disc is set rolign wioth a speed v on the horizontal part of the track of the previous problem from right to left. To what height will it climb up the curved part?

Answer

B, C, D

Explanation

A disc is set rolling with a velocity v from right to left. It has attained a height h, therefore
`1/2mV^2+1/2Iomega^2=mgh`
`rarr 1/2mV^2+1/2xx1/2mR^2omega^2=mgh`
`rarr 1/2V^2+1/4V^2=gh` ltbr.gt `rarr (3/4)V^2=gh`
`rarr (3/4)V^2=gh`
`rarr h=(3/4(v^2/g)`