Question

hree identical solid spheres move down three inclines A, B and C—all of the same dimensions. A is without friction, the friction between B and a sphere is sufficient to cause rolling without slipping, the friction between C and a sphere causes rolling with slipping. The kinetic energies of A, B, C at the bottom of the inclines are E_A, E_B, E_C.

(a) E_A = E_B = E_C 

(b) E_A = E_B > E_C 

(c) E_A > E_B > E_C 

(d) E_A > E_B = E_C

Answer 1

Correct Answer is: (b) E_A = E_B > E_C 

Hence, kinetic energy = loss in gravitational potential energy. In rolling with slipping, some energy is lost in doing work against friction, and kinetic energy is less than the loss in potential energy.