Question

A solid sphere of mass 5 kg and radius 10 m is rolling purely on a horizontal surface as shown in the figure. The separation of P from A (point of contact) is 7 m. If the sphere has an angular velocity about an axis through its centre of mass as 2 $\frac{rad}{sec},$ what is the speed of the point P at this instant ?

• A. 18 m/s
• B. 14 m/s
• C. 20 m/s
• D. 32 m/s

Answer 1

The correct option is B 14 m/s

We can assume the sphere purely rotating about point A.
This implies the speed of P will just be = l$\omega$
where, l = length of AP.
$\Rightarrow (speed{)}_p=7\times 2=14\frac{m}{s}.$