Question

A model train with a mass of `4 kg` is moving along a track at `21 (cm)/s`. If the curvature of the track changes from a radius of `42 cm` to `140 cm`, by how much must the centripetal force applied by the tracks change?

Answer 1

The change in centripetal force is `=0.294N`

Explanation:

The centripetal force is

`F=(mv^2)/r`

The mass is of the train `m=4kg`

The velocity of the train is `v=0.21ms^-1`

The radii are

`r_1=0.42m`

and

`r_2=1.40m`

The variation in the centripetal force is

`DeltaF=F_2-F_1`

The centripetal forces are

`F_1=4*0.21^2/0.42=0.42N`

`F_2=4*0.21^2/1.40=0.126N`

`DeltaF=F_1-F_2=0.42-0.126=0.294N`