A model train with a mass of 2 kg is moving along a track at 36 (cm)/s. If the curvature of the track changes from a radius of 6 cm to 3 cm, by how much must the centripetal force applied by the tracks change?

1 Answer
Mar 5, 2017

4.32N

Explanation:

Put the values we have into SI units:

36cms^-1 = 0.36ms^-1
6cm = 0.06m
3cm = 0.03m

The equation for centripetal force is

F = (mv^2)/r

so the change in centripetal force is

DeltaF = (mv^2)/r_2 - (mv^2)/r_1

Plug in the values we are given,

DeltaF = (2 xx 0.36^2)/0.03 - (2 xx 0.36^2)/0.06

= 8.64 - 4.32 = 4.32N