Question

A model train, with a mass of `3 kg`, is moving on a circular track with a radius of `2 m`. If the train's rate of revolution changes from `5/3 Hz` to `1/8 Hz`, by how much will the centripetal force applied by the tracks change by?

Answer 1

The change in centripetal force is `=654.3N`

Explanation:

The centripetal force is

`F=(mv^2)/r=mromega^2N`

The mass of the train, `m=(3)kg`

The radius of the track, `r=(2)m`

The frequencies are

`f_1=(5/3)Hz`

`f_2=(1/8)Hz`

The variation in centripetal force is

`DeltaF=F_2-F_1`

`F_1=mromega_1^2=mr*(2pif_1)^2=3*2*(2pi*5/3)^2=658.0N`

`F_2=mromega_2^2=mr*(2pif_2)^2=3*2*(2pi*1/8)^2=3.7N`

`DeltaF=F_1-F_2=658-3.7=654.3N`