Question

A stone tied to be the end of string 2m long is whield in a horizontal circular with constant speed. If the stone makes 10 revolution in 20 seconds calculate the magnitude and direction of acceleration.​

Answer 1

Answer:

Given:

2m long string is made to move in a horizontal circle. 10 revolutions in 20 seconds.

To find:

Magnitude and direction of acceleration

Concept:

In a uniform circular motion, there is only 1 type of acceleration experienced by the object. It is centripetal acceleration directed radially inwards towards the centre of the circle.

Calculation:

10 revolutions made in 20 seconds

so, 1 revolution made in 20/10 = 2 sec.

Now circumference

= 2 × π × r

= 2 × π × 2

= 4π.

So velocity = distance/time

=> v = 4π/2

=> v = 2π.

So centripetal acceleration

= v²/r

= (2π)²/2

= 4π²/2

= 2π² m/s².

So the centripetal acceleration is directed radially inwards towards the centre of the horizontal circle.