Question

A model train, with a mass of `4 kg`, is moving on a circular track with a radius of `5 m`. If the train's rate of revolution changes from `1/9 Hz` to `1/3 Hz`, by how much will the centripetal force applied by the tracks change by?

Answer 1

The centripetal force change by `=39N`

Explanation:

The centripetal force is

`F=mr omega^2`

mass is `m=4kg`

radius `r=5m`

`Delta omega=(1/3-1/9)*2pi=(4/9pi)rads^-1`

The variation in centripetal force is

`DeltaF=mr(Delta omega)^2`

`=4*5*(4/9pi)^2`

`=39N`