# DDP Chapter 7

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# Links for the Seventh Chapter

This video shows the International Space Station (which is in uniform circular motion around the earth) passing between the earth and the moon.

This video has a couple of demonstrations of centripetal force (the guy pronounces it strangely).

This video uses fishing bobbers as accelerometers to demonstrate the direction of the centripetal force.

This video shows you how to calculate speed from period and radius.

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This video shows you how to calculate centripetal force from radius and speed.

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This video has some idiot showing you what happens when the centripetal force exceeds the ability of a string to provide it.

This video shows you how to solve a problem with a car taking a curve.

Explanation of the Cavendish Experiment
This website explains the Cavendish Experiment

This video shows that the small balls really do move towards the big balls in the Cavendish Experiment.

This video shows you how to use the gravitational force equation.

This video shows you how to use the gravitational force and centripetal force equations together.

Accurate animation of planet speeds in the solar system
This animation shows the relative speeds of the planets in the solar system. You can click on the names at the top to get a pointer indicating where the sun/planet is. Also, note that the relative distances and sizes are not accurate. The solar system is very hard to draw to scale because of the varying sizes and distances.

This video shows a scale model of the solar system that you can find in Melbourne, Australia.

This video explains Kepler’s Laws.

In this video, an interesting YouTube personality explains why centrifugal force isn’t real.

Extra Practice Problems for Chapter 7
The solutions for these problems can be found here.