Question

A model train with a mass of `4 kg` is moving along a track at `18 (cm)/s`. If the curvature of the track changes from a radius of `25 cm` to `14 cm`, by how much must the centripetal force applied by the tracks change?

Answer 1

The change in centripetal force is `=0.41N`

Explanation:

The centripetal force is

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

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

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

The radii of the tracks are

`r_1=0.25m`

and

`r_2=0.14m`

The variation in the centripetal force is

`DeltaF=F_2-F_1`

The centripetal forces are

`||F_1||=4*0.18^2/0.25=0.518N`

`||F_2||=4*0.18^2/0.14=0.926N`

`DeltaF=|F_1-F_2|=0.926-0.518=0.41N`