A model train with a mass of #4 kg# is moving along a track at #21 (cm)/s#. If the curvature of the track changes from a radius of #42 cm# to #90 cm#, by how much must the centripetal force applied by the tracks change?

1 Answer
Nov 26, 2017

Answer:

The centripetal force changes by #=0.224N#

Explanation:

The centripetal force is

#F=(mv^2)/r#

The mass is #m=4kg#

The velocity is #v=0.21ms^-1#

The radii are

#r_1=0.42m#

and

#r_2=0.9m#

The variation in centripetal force is

#DeltaF=F_2-F_1#

The centripetal forces are

#F_1=4*0.21^2/0.42=0.42N#

#F_2=4*0.21^2/0.9=0.196N#

#DeltaF=0.42-0.196=0.224N#