Question

A stone tied to the end of a string of 1 m long is whirled in a horizontal circle with a constant speed. If the stone makes 22 revolutions in 44 seconds, what is the magnitude and direction of acceleration of the stone?

(a)  π²m s^-2 and direction along the radius towards the centre

(b)  π²m s^-2 and direction along the radius away from the centre

(c)    π² m s^-2 and direction along the tangent to the circle

(d)    π²/4 ms^-2 and direction along the radius towards the centre.

Answer 1

Correct option  (a,b)

Explanation:

Towards the centre, the centripetal acceleration

 = - ω²R

and away from the centre, the centrifugal acceleration is +ω²R.

.'. (a) and (b) are correct as the directions are given.