A model train, with a mass of 3 kg, is moving on a circular track with a radius of 3 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?

1 Answer
May 9, 2018

The change in centripetal force is =6N

Explanation:

The mass of the train is m=3kg

The radius of the track is r=3m

The centripetal force is

F=(mv^2)/r

v^2=(Fr)/m

The kinetic energy is

KE=1/2mv^2

Therefore,

The variation of kinetic energy is

DeltaKE=1/2m(v_1^2-v_2^2)

v_1^2=(F_1r)/m

v_2^2=(F_2r)/m

So,

DeltaKE=1/2m((F_1r)/m-(F_2r)/m)=r/2(F_2-F_1)=r/2DeltaF

DeltaF=2/rDeltaKE

The change in centripetal force is

DeltaF=2/3*(27-18)=6N