Question

A mass moves on a circular path of radius 2 m at constant speed 4m/s, what is the magnitude and direction of the average acceleration during a quarter of a revolution?

Answer 1

`abs ( vec a) = 8 m/s^2` in direction `- hat r`

Explanation:

at constant speed, the acceleration throughout is

`vec a = - v^2/r hat r = - 4^2/2 hat r = - 8 hat r`

so `abs ( vec a) = 8 m/s^2` and it is in direction `- hat r`, ie inward radial.