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 `24 cm` to `42 cm`, by how much must the centripetal force applied by the tracks change?

Answer 1

The centripetal force applied by the tracks change is `F_c=1.62N`.

Explanation:

Centripetal force `F_c=mv^2/r`
As we know change in force '`DeltaF_c`' is inversely proportional to the change in the radius '`Deltar`'.
So `Deltar=42cm-24cm=18cm`
Conversion into metres for SI units `:.Deltar=18xx10^-2metre`.
Similarly to the velocity`:.v=18xx10^-2m//s`.
Substituting these values in above force equation we get,
`F_c={(9kg)(18xx10^-2m//s)^2}/(18xx10^-2m)=1.62N`.