Question

A model train, with a mass of `3 kg`, is moving on a circular track with a radius of `1 m`. If the train's kinetic energy changes from `18 j` to `27 j`, by how much will the centripetal force applied by the tracks change by?

Answer 1

The change in centripetal force should be 18 N

Explanation:

we know KE =(1/2)XmassX(velocity)^2
intial KE being 18J then massX(initial vel)^2 =36 J
and initial centripetal force ={massX(initial vel)^2}/radius
= 36 N (radius = 1m)
similarly we
final centripetal force = 54 N
Hence change in force = 18 N