Question

A rock weighing 20 n (mass = 2 kg) is swung in a horizontal circle of radius 2 m at a constant speed of 6 m/s. what is the centripetal acceleration of the rock?

Answer 1

Centripetal acceleration, same as the linear acceleration, is the rate of change of velocity but in this case the tangential velocity. The direction of this acceleration is always directed inward the motion. Centripetal acceleration is calculated from the ratio of the square of the velocity and the radius. We calculate as follows:

centripetal acceleration = v^2 / r
centripetal acceleration = ( 6 m/s )^2 / 2 m
centripetal acceleration = 18 m/s^2

Answer 2

Answer:

$a_c = 18 m/s^2$

Explanation:

As we know that the centripetal acceleration is defined as the ratio of square of the speed and the radius of the circle

so it is given as

$a_c = \frac{v^2}{R}$

here we know that

speed of the rock moving in horizontal circle is given as

$v = 6 m/s$

also we know the radius of circle is

$R = 2 m$

now we have

$a_c = \frac{v^2}{R}$

$a_c = \frac{6^2}{2}$

$a_c = 18 m/s^2$