# A model train, with a mass of #12 kg#, is moving on a circular track with a radius of #9 m#. If the train's rate of revolution changes from #6 Hz# to #4 Hz#, by how much will the centripetal force applied by the tracks change by?

##### 1 Answer

The centripetal force will decrease by a factor of

#### Explanation:

Just learnt circular motion today so . . . umm, answer might not be 100% correct. Anyhow, we first need to find the angular speed to find centripetal force. Angular speed is found using

Now to find centripidal force, we need the equation

Placing our values into this formula, we get

Thus, we can now find the difference between the centripetal force applied by the tracks.

Hope this helps.