Rolling on Inclined Plane - NEET Physics Questions
← Back to Rotational Motion

Rolling on Inclined Plane

Question 1:

A sphere rolls down an inclined plane through a height h. Its velocity at the bottom would be

1. \[ \sqrt[]{2gh} \]
2. \[ \sqrt[]{\frac{7}{10}gh} \]
3. \[ \sqrt[]{\frac{10}{7}gh} \]
4. \[ \left( \sqrt[]{\frac{10}{7}} \right)gh \]
View Answer

\[ mgh=\frac{1}{2}mv^{2} + \frac{1}{2}I\omega^{2}= \frac{1}{2}mv^{2}+ \frac{1}{2}(\frac{2}{5}mR^{2})\frac{v^{2}}{R^{2}} \]

Solving we get,

\[ v=  \sqrt[]{\frac{10}{7}gh} \]

Question 2:

A body rolls down an inclined plane. If its kinetic energy of rotation is 40% of its kinetic energy of translation, then the body is

1. Solid cylinder
2. Solid sphere
3. Disc
4. Ring
View Answer

Given, rotational kinetic energy is 40% of total energy. so,

\[ \frac{1}{2}I\omega^{2}=\frac{40}{100}\left( \frac{1}{2}mv^{2} + \frac{1}{2}I\omega^{2} \right) \]

Solving ,

\[ I = \frac{2}{5}mR^{2} \]

Object is Solid Sphere.