Answer:
63J
Explanation:
The question tells us that they both have a kinetic energy of 126 J. What we are required to get is the rotation kinetic energy of the ring
Total kinetic energy =
1/2mv² + 1/2IW²
For ring,
I = mr²
And v = Rw for pure rolling
The total kinetic energy
= 1/2mr² + 1/2mv²
= 126J
126/2
= 63J
The rotational kinetic energy of the ring is therefore 63J.
Thank you!
