Question

A model train, with a mass of `4 kg`, is moving on a circular track with a radius of `3 m`. If the train's kinetic energy changes from `8 j` to `48 j`, by how much will the centripetal force applied by the tracks change by?

Answer 1

`deltaF=26.6666666666.......N`

Explanation:

Given we have to find the centripetal force on a model train of mass `m=4kg` which is moving in a circular track of radius `r=3m`

The centripetal force of a body is `F=mv^2/r` and the kinetic energy of a body is `K=1/2mv^2\implies2k=mv^2`
Substituting `K` in `F`, we get `F=2K/r` or `deltaF=2/r\deltaK`

Here, `deltaK=48-8=40J`
So, change in centripetal force applied by tracks change by `deltaF=2*40/3`

Um.....yeah, that's why you end up with `666666`s