Question

A model train, with a mass of `32 kg`, is moving on a circular track with a radius of `3 m`. If the train's kinetic energy changes from `18 j` to `21 j`, by how much will the centripetal force applied by the tracks change by?

Answer 1

`2N`

Explanation:

suppose,initial velocity was `u` and then final velocity became `v`,so for a mass of `m`,we can say,its change in kinetic energy will be, `1/2 m(v^2-u^2)=21-18=3`

so, `m(v^2-u^2)=6......................1`

Now,change in centripetal force will be `m/r(v^2 - u^2)=6/r=6/3=2N` (from `1` and given, `r=3m`)