A model train with a mass of #5 kg# is moving along a track at #14 (cm)/s#. If the curvature of the track changes from a radius of #84 cm# to #21 cm#, by how much must the centripetal force applied by the tracks change?

1 Answer
Dec 17, 2017

The change in centripetal force is #=0.35N#

Explanation:

The centripetal force is

#F=(mv^2)/r#

The mass is of the train #m=5kg#

The velocity is #v=0.14ms^-1#

The radii are

#r_1=0.84m#

and

#r_2=0.21m#

The variation in the centripetal force is

#DeltaF=F_2-F_1#

The centripetal forces are

#F_1=5*0.14^2/0.84=0.117N#

#F_2=5*0.14^2/0.21=0.467N#

#DeltaF=0.467-0.117=0.35N#