Question

A model train, with a mass of `2 kg`, is moving on a circular track with a radius of `9 m`. If the train's rate of revolution changes from `5 Hz` to `2 Hz`, by how much will the centripetal force applied by the tracks change by?

Answer 1

The change in centripetal force is `=14922.9N`

Explanation:

The centripetal force is

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

The mass of the train, `m=(2)kg`

The radius of the track, `r=(9)m`

The frequencies are

`f_1=(5)Hz`

`f_2=(2)Hz`

The angular velocity is `omega=2pif`

The variation in centripetal force is

`DeltaF=F_2-F_1`

`F_1=mromega_1^2=mr*(2pif_1)^2=2*9*(2pi*5)^2=17765.3N`

`F_2=mromega_2^2=mr*(2pif_2)^2=2*9*(2pi*2)^2=2842.4N`

`DeltaF=F_2-F_1=17765.3-2842.4=14922.9N`