# A model train with a mass of 4 kg is moving along a track at 9 (cm)/s. If the curvature of the track changes from a radius of 180 cm to 63 cm, by how much must the centripetal force applied by the tracks change?

##### 1 Answer
Feb 14, 2017

The centripetal force changes by $0.028 N$

#### Explanation:

The centripetal force is

$F = \frac{m {v}^{2}}{r}$

The change in centripetal force is

$\Delta F = \frac{m {v}^{2}}{\Delta r}$

So,

$\Delta F = \frac{4 \cdot {0.09}^{2}}{1.8 - 0.63} = \frac{0.0324}{1.17} N$

$= 0.028 N$