Question

A model train, with a mass of `3 kg`, is moving on a circular track with a radius of `8 m`. If the train's rate of revolution changes from `1/4 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 `=44.4N`

Explanation:

The centripetal force is

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

The mass, `m=(3)kg`

The radius, `r=8m`

The frequencies are

`f_1=1/4=0.25Hz`

`f_2=1/8=0.125Hz`

The variation in centripetal force is

`DeltaF=F_2-F_1`

`F_1=mromega_1^2=mr*(2pif_1)^2=3*8*(2pi*0.25)^2=59.2N`

`F_2=mromega_2^2=mr*(2pif_2)^2=3*8*(2pi*0.125)^2=14.8N`

`DeltaF=F_1-F_2=59.2-14.8=44.4N`