Question

An object with a mass of `4 kg` is revolving around a point at a distance of `5 m`. If the object is making revolutions at a frequency of `5 Hz`, what is the centripetal force acting on the object?

Answer 1

Centripetal force is `19739.21N`

Explanation:

Centripetal force acting on a body in circular motion is given by

`F_c=(mv^2)/r`, where`m` is mass, `v` is velocity and `r` is the radius

As object moves at a frequency of `fHz`, it means it moves

`2pirxxf` in `1` second and hence `v=2pirf`

and `F_c=m/rxx4pi^2r^2f^2=4pi^2mrf^2`

aas `m=4kg`, `f=5Hz` and `r=5m`

`F_c=4pi^2xx4xx5xx5^2=2000pi^2=19739.21N`

Answer 2

The centripetal force is `=19.739kN`

Explanation:

The centripetal force is

`F=mv^2/r=mr omega^2`

The mass is `m=4kg`

The radius is `r=5m`

The angular velocity is `omega=2pif=10pi`

Therefore,

`F=4*5*(10pi)^2=19739N`