Question

1-5 The ball is tied to a string to whirl it having a radius of 40.0 cm at a velocity of 2.5 m/s. What will be

the acceleration of the ball?

Answer 1

The centripetal acceleration 

$$a=\frac{v^2}{R}=\frac{2.5^2}{0.20}=31\:\rm m/s^2$$