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

1 Answer
Jul 20, 2017

The change in certipetal force is #=0.084N#

Explanation:

The centripetal force is

#F=(mv^2)/r#

mass, #m=4kg#

speed, #v=0.21ms^-1#

radius, #=(r) m#

The variation in centripetal force is

#DeltaF=F_2-F_1#

#F_1=mv^2/r_1=4*0.21^2/4.2=0.042N#

#F_2=mv^2/r_2=4*0.21^2/1.4=0.126N#

#DeltaF=0.126-0.042=0.084N#