A stone tied to end of a string ` 80 cm` long is whirled in a horizontal plane with a constant speed. If the stone makes ` 14` revolutions in ` 25` seconds, what is the magnitude and direction of acceleration of the stone ?

Explanation

Here, r=80cm = 0.8 m,
`v=14/25 rev//s`.
`omega = 2piv= 2 xx 22/7 xx 14/25rad//s = 88/55rad s^(-1)`
The centripetal acceleration, `a=omega^(2)r = (88/25)^(2) xx 0.80 = 9.90 ms^(-2)`
The direction of centripetal acceleration is along the string directed towards the center of circular path.