A model train with a mass of 4 kg4kg is moving along a track at 18 (cm)/s18cms. If the curvature of the track changes from a radius of 84 cm84cm to 42 cm42cm, by how much must the centripetal force applied by the tracks change?

1 Answer
Mar 22, 2018

The change in centripetal force is =0.155N=0.155N

Explanation:

The centripetal force is

vecF_C=(mv^2)/r*vecrFC=mv2rr

The mass is of the train m=4kgm=4kg

The velocity of the train is v=0.18ms^-1v=0.18ms1

The radii of the tracks are

r_1=0.84mr1=0.84m

and

r_2=0.42mr2=0.42m

The variation in the centripetal force is

DeltaF=F_2-F_1

The centripetal forces are

||F_1||=4*0.18^2/0.84=0.154N

||F_2||=4*0.18^2/0.42=0.309N

DeltaF=F_1-F_2=0.154-0.309=-0.155N