Question

A solid sphere, a hollow sphere and a solid cylinder, all having equal mass and radius, are placed at the top of an incline and released. The friction coefficients between the objects and the incline are equal and but not sufficient to allow pure rolling. Greastest time will be taken in reaching the bottom by

• A. The solid sphere
• B. The hollow sphere
• C. The solid cylinder
• D. All will take same time.

Answer 1

The correct option is D All will take same time.

As the three objects viz solid sphere, hollow sphere and solid cylinder will slip, the friction for all three objects will be same. Also the angle(mgSin$\theta$) is same for all, thus the net force and hence the acceleration will be same for all three. Thus it will be displayed by same distance and will reach the bottom at the same time.