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 #140 cm#, by how much must the centripetal force applied by the tracks change?

1 Answer
Jan 25, 2018

Answer:

The change in centripetal force is #=0.294N#

Explanation:

The centripetal force is

#F=(mv^2)/r#

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

The velocity of the train is #v=0.21ms^-1#

The radii are

#r_1=0.42m#

and

#r_2=1.40m#

The variation in the 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*0.21^2/1.40=0.126N#

#DeltaF=F_1-F_2=0.42-0.126=0.294N#