A model train, with a mass of 5 kg, is moving on a circular track with a radius of 9 m. If the train's kinetic energy changes from 25 j to 40 j, by how much will the centripetal force applied by the tracks change by?

1 Answer
Feb 23, 2017

The change in centripetal force is =3.33N

Explanation:

The centripetal force is

F=(mv^2)/r

The kinetic energy is

KE=1/2mv^2

The variation of kinetic energy is

Delta KE=1/2mv^2-1/2m u^2

=1/2m(v^2-u^2)

The variation of centripetal force is

DeltaF=m/r(v^2-u^2)

=2/r*1/2m(v^2-u^2)

=2/r*Delta KE

=2/9*(40-25)N

=2/9*15N

=3.33N