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 `4 j` to `15 j`, by how much will the centripetal force applied by the tracks change by?

Answer 1

`22/3N`

Explanation:

we know that the change in kinetic energy of the system
`DeltaE_k=1/2m(v_f^2-v_i^2)`

we also know that change in centripetal force is
centripetal force =`(mv^2)/r` or change in centripetal force =`m(v_f^2-v_i^2)/r`
so we gonna substitute the values we get

`(v_f^2-v_i^2)=2*DeltaE_k/m=11/2`

we put this value in centripetal force change equation we get

`m*11/2*1/r=(4*11)/(2*3)=22/3N`