Angular speed at bottom of loop

[Paulie71199]

Homework Statement

A circular ring with a mass of 11 kg and radius of 0.66 meters is to roll without slipping about a vertical loop of radius 10 meters which is frictionless. If it is to just barely make it around the top of the loop, what must its angular speed be at the bottom of the loop in rad/s?

Homework Equations

The moment of inertia for the ring about it's center is I = M R2.

The Attempt at a Solution

The answer comes to be 25.99 rads/sec. Although I don't know how to get to that answer

 

[tiny-tim]

Welcome to PF!

Hi Paulie! Welcome to PF!

(have a theta: θ and try using the X² icon just above the Reply box )

Use conservation of energy (together with the rolling equation relating speed of centre of mass to angular velocity, and putting hte normal reaction force equal to zero at the top).

 

[Paulie71199]

Thank you for the welcome and the help!

Thanks for the tip lol.