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

Answer –

According to the question, the length of the string, l is 80 cm, or 0.8 m

and the number of revolutions is 14

And the time taken = 25 s

Expression for the frequency is given as follows –

Frequency (v) = Number of revolutions / Time taken

v = 14 / 25 Hz

Angular frequency is given as follows –

Expression for centripetal acceleration is as follows :

At all times, the direction of centripetal acceleration is always along the string, toward the centre.