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  • 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.

Nearly 350 years ago, Isaac Newton came up with three laws of motion that govern how everything moves.

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