Question

A body is rolling down an inclined plant. If K.E. of rotation is 40% of K.E. in translatory state, then the body is a:

• A. Ring
• B. Cylinder
• C. Hollow ball
• D. Solid ball

Answer 1

Answer: (D)

Solid ball

Answer 2

$\frac { 1 } { 2 } m v ^ { 2 } \left( \frac { K ^ { 2 } } { R ^ { 2 } } \right) = 40 \%$ $\frac { 1 } { 2 } m v ^ { 2 }$ ⇒ $\frac { K ^ { 2 } } { R ^ { 2 } } = \frac { 40 } { 100 }$ $= \frac { 2 } { 5 }$ i.e. the body is solid circle