A sphere of radius 1 m is kept on a plank kept on horizontal surface. Accelerations of plank and centre of sphere are indicated in the figure.

If sphere is not slipping on the plank then its angular acceleration is

Options

A. `8"rad"//s^(2)`
B. `6"rad"//s^(2)`
C. `4"rad"//s^(2)`
D. `2"rad"//s^(2)`

Answer

A

Explanation

Acceleration of centre of sphere with respect to plank is `a=5+3=8m//s^(2)`.
For pure rolling we can write `a=ralphaimpliesalpha=8//1=8rad//s^(2)`. Hence