A model train with a mass of 9 kg is moving along a track at 18 (cm)/s. If the curvature of the track changes from a radius of 32 cm to 45 cm, by how much must the centripetal force applied by the tracks change?

1 Answer
Apr 17, 2016

-0.26325N

Explanation:

Centripetal (center-seeking) force is given by the equation

F=(mv^2)/r,

where m is mass, v is velocity and r is radius.

At the beginning, when the radius is 0.32m and velocity 0.18ms^-1, the centripetal force would be

F=(9kg*0.0324m^2s^-2)/(0.32m)
0.91125N

In the second part, when the radius has expanded to 0.45m, centripetal force is

F=(9kg*0.0324m^2s^-2)/(0.45m)
=0.648N

The change in centripetal force is then found by simple subtraction,

DeltaF=0.648N-0.91125N
=-0.26325N