A model train with a mass of 4 kg4kg is moving along a track at 21 (cm)/s21cms. If the curvature of the track changes from a radius of 420 cm420cm to 140 cm140cm, 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=0.084N

Explanation:

The centripetal force is

F=(mv^2)/rF=mv2r

mass, m=4kgm=4kg

speed, v=0.21ms^-1v=0.21ms1

radius, =(r) m=(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