Three Incorrect Laws of Motion

Nearly 350 years ago, Isaac Newton came up with three laws of motion that govern how everything moves. There are three pretty famous laws of motion. And they're not very complicated, but if I told them to you as clearly as I can, you would think that you're understanding them, but I think you wouldn't. And the reason is, everyone has ideas about physics and how objects move before they're ever taught anything in, uh, a science classroom.

So rather than tell you Newton's Three Laws of Motion, I like to tell you Derek's Three Incorrect Laws of Motion, which are the ones I think you're actually thinking.

So, Derek's First Incorrect Law of Motion is... An object with no unbalanced forces on it will naturally come to rest.

[Cup sliding]
[Books falling]
[Door slamming]
[Coin spinning and falling]

Derek's Second Incorrect Law of Motion is that an unbalanced force causes an object to move with a constant velocity. We could express this in an equation where the unbalanced force, F, equals the mass (M) times the velocity (V). So, if you double the force, the velocity also doubles. It's just like being in a car. As you press on the accelerator, you increase the force on the car, and therefore, you move to a new, higher constant speed.

Derek's Third Incorrect Law of Motion is that larger objects apply larger forces to smaller objects. When a large truck slams into a car on the highway, the force of the truck on the car is much greater than the force of the car back on the truck. Or you think about the Earth and the Moon. The force with which the Earth attracts the Moon is greater than the force with which the Moon attracts the Earth.

But remember, this is an incorrect law of motion.