A hollow cylinder of mass M and radius R rolls down an inclined plane. A block of mass M easily slides down an identical inclined plane. Complete the following statement: If both objects are released at the same time from the top of their inclined planes,

A) the cylinder will reach the bottom first.
B) the block will reach the bottom first.
C) the block will reach the bottom with the greater kinetic energy.
D) the cylinder will reach the bottom with the greater kinetic energy.
E) both the block and the cylinder will reach the bottom at the same time.

Explanation:

block will go down with acceleration = g sinθ

cylinder will go down with acceleration

= g sinθ / (1 + k² / r²)

this value is less than g sinθ

so block will have greater acceleration so it will reach bottom earlier.

A ) is correct.

the block will reach the bottom with the greater kinetic energy.

C ) is correct

Both the body loses same potential energy but cylinder will have both rotational and linear kinetic energy . Hence cylinder will have less kinetic energy because their linear velocity is less. It is due to distribution of potential energy into rotational and linear kinetic energy.