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

##### 1 Answer

Jan 25, 2018

The change in centripetal force is

#### Explanation:

The centripetal force is

The mass is of the train

The velocity of the train is

The radii are

and

The variation in the centripetal force is

The centripetal forces are