Question

A hollow sphere of diameter 0.2 m and mass 2 kg is rolling on an inclined plane with velocity v = 0.5 m/s. The kinetic energy of the sphere is:

• A. 0.1 J
• B. 0.3 J
• C. 0.5 J
• D. 0.42 J.

Answer 1

Answer: (D)

0.42 J.

Answer 2

$\mathrm { K } _ { \mathrm { N } } = \frac { 1 } { 2 } \mathrm { mv } ^ { 2 } \left( \frac { \mathrm { K } ^ { 2 } } { \mathrm { R } ^ { 2 } } + 1 \right) = \frac { 1 } { 2 } \times 2 \times ( 0.5 ) ^ { 2 } \times \left( \frac { 2 } { 3 } + 1 \right) = 0.42 \mathrm {~J}$