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 `90 cm`, by how much must the centripetal force applied by the tracks change?

Answer 1

The centripetal force changes by `=0.224N`

Explanation:

The centripetal force is

`F=(mv^2)/r`

The mass is `m=4kg`

The velocity is `v=0.21ms^-1`

The radii are

`r_1=0.42m`

and

`r_2=0.9m`

The variation in 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*0.21^2/0.9=0.196N`

`DeltaF=0.42-0.196=0.224N`