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 #84 cm# to #70 cm#, by how much must the centripetal force applied by the tracks change?

1 Answer
Aug 30, 2017

Answer:

The change in centripetal force is #=0.042N#

Explanation:

The centripetal force is

#F=(mv^2)/r#

The mass, #m=(4)kg#

The speed, #v=(0.21)ms^-1#

The radius, #=(r) m#

The variation in centripetal force is

#DeltaF=F_2-F_1#

#F_1=mv^2/r_1=4*0.21^2/0.84=0.21N#

#F_2=mv^2/r_2=4*0.21^2/0.70=0.252N#

#DeltaF=0.252-0.21=0.042N#