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

1 Answer
Joseph W.
Aug 8, 2017

The centripetal force will decrease by a factor of 94 or more exactly, by 8640N

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

ω=2πT, where ω is the angular speed, and T is time taken for 1 rotations. When a object has 6Hz for circular motion, than it means it rotates around the path 6 time per second and thus. will only take 16 for 1 rotation. Likewise, 4Hz will have a T value of 14. Finding the angular speed for both, we get

ω=12π for the 6Hz train

ω=8π for the 4Hz train

Now to find centripidal force, we need the equation

F=mω2r, were m= mass (kg) and r=radius of rotation.

Placing our values into this formula, we get

F=15552πN for the 6Hz train

F=6912πN for the 4Hz train

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

Hope this helps.

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