# A model train, with a mass of #8 kg#, is moving on a circular track with a radius of #1 m#. If the train's rate of revolution changes from #5/3 Hz# to #1/4 Hz#, by how much will the centripetal force applied by the tracks change by?

##### 1 Answer

#### Answer:

#### Explanation:

In order to get the centripetal force for each instance we need to substitute mass, velocity and radius into the following equation:

Hertz are revolutions per second therefore we can calculate the velocity of the train in both situations.

So first calculate the distance of the track:

I will leave the result in terms of pi for accuracy.

So

Therefore since we know that a hertz is revolutions per second so know the time and we can obtain the distance by multiplying the hertz by the distance of track. So the velocity of the first

For the

Now since we have all of the variables for the force calculation substitute them into that equation:

And

Go ahead and calculate the difference: