Question

A model train with a mass of `9 kg` is moving along a track at `18 (cm)/s`. If the curvature of the track changes from a radius of `36 cm` to `42 cm`, by how much must the centripetal force applied by the tracks change?

Answer 1

The change in centripetal force is `=0.12N`

Explanation:

The centripetal force is

`vecF_C=(mv^2)/r*vecr`

The mass is of the train `m=9kg`

The velocity of the train is `v=0.18ms^-1`

The radii of the tracks are

`r_1=0.36m`

and

`r_2=0.42m`

The variation in the centripetal force is

`DeltaF=F_2-F_1`

The centripetal forces are

`||F_1||=9*0.18^2/0.36=0.81N`

`||F_2||=9*0.18^2/0.42=0.69N`

`DeltaF=|F_1-F_2|=0.81-0.69=0.12N`