A particle moves in a circle of radius 4 cm clockwise at constant speed 2 cm/s. If `hatx` and `haty` are unit acceleration vectors along X and Y-axis respectively (in `cm//s^2`), the acceleration of the particle at the instant half way between P and Q is given by

Options

A. `-4(hatx+haty)`
B. `4(hatx+haty)`
C. `-(hatx+haty)//sqrt2`
D. `(hatx-haty)//4`

Answer

C

Explanation

`a=v^2/r`=1 cm/s . Centripetal acceleration is directed towards the centre. Its magnitude =1. Unit vector at the mid point on the path between P and Q is `-(hatx+haty)//sqrt2` .