Question

A model train, with a mass of `4 kg`, is moving on a circular track with a radius of `8 m`. If the train's kinetic energy changes from `32 j` to `0 j`, by how much will the centripetal force applied by the tracks change by?

Answer 1

`8N`

Explanation:

Centripetal force is given as `F_c = (mv^2)/r = ("2 K.E.")/r`.

Hence, `Delta F_c = (2 Delta"K.E.")/r = (2*(32-0) J)/(8m) = 8 N`