A model train with a mass of 9 kg9kg is moving along a track at 18 (cm)/s18cms. If the curvature of the track changes from a radius of 36 cm36cm to 42 cm42cm, by how much must the centripetal force applied by the tracks change?

1 Answer
Aug 1, 2018

The change in centripetal force is =0.12N=0.12N

Explanation:

The centripetal force is

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

The mass is of the train m=9kgm=9kg

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

The radii of the tracks are

r_1=0.36mr1=0.36m

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||=9*0.18^2/0.36=0.81N

||F_2||=9*0.18^2/0.42=0.69N

DeltaF=|F_1-F_2|=0.81-0.69=0.12N