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 `5/4 Hz` to `3/8 Hz`, by how much will the centripetal force applied by the tracks change by?

Answer 1

The change in centrpetal force `=336.8N`

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=(5/4)Hz`

`f_2=(3/8)Hz`

The variation in centripetal force is

`DeltaF=F_2-F_1`

`F_1=mromega_1^2=mr*(2pif_1)^2=3*2*(2pi*5/4)^2=370.1N`

`F_2=mromega_2^2=mr*(2pif_2)^2=3*2*(2pi*3/8)^2=33.3N`

`DeltaF=F_1-F_2=370.1-33.3=336.8N`