# A model train, with a mass of 4 kg, is moving on a circular track with a radius of 5 m. If the train's rate of revolution changes from 1/9 Hz to 1/3 Hz, by how much will the centripetal force applied by the tracks change by?

Mar 30, 2017

The centripetal force change by $= 39 N$

#### Explanation:

The centripetal force is

$F = m r {\omega}^{2}$

mass is $m = 4 k g$

radius $r = 5 m$

$\Delta \omega = \left(\frac{1}{3} - \frac{1}{9}\right) \cdot 2 \pi = \left(\frac{4}{9} \pi\right) r a {\mathrm{ds}}^{-} 1$

The variation in centripetal force is

$\Delta F = m r {\left(\Delta \omega\right)}^{2}$

$= 4 \cdot 5 \cdot {\left(\frac{4}{9} \pi\right)}^{2}$

$= 39 N$