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 `2/5 Hz` to `5/6 Hz`, by how much will the centripetal force applied by the tracks change by?

Answer 1

The change in centripetal force is `=501.1N`

Explanation:

The centripetal force is

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

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

The radius, `r=2m`

The frequencies are

`f_1=2/5=0.4Hz`

`f_2=5/6=0.83Hz`

The variation in centripetal force is

`DeltaF=F_2-F_1`

`F_1=mromega_1^2=mr*(2pif_1)^2=3*8*(2pi*0.4)^2=151.6N`

`F_2=mromega_2^2=mr*(2pif_2)^2=3*8*(2pi*0.83)^2=652.7N`

`DeltaF=F_1-F_2=652.7-151.6=501.1N`