Sir Isaac Newton developed three laws of motion. The first law of inertia says that an object’s speed will not change unless something makes it change. The second law: the strength of the force equals the mass of the object times the resulting acceleration. Finally, the third law says that for every action there is a reaction. In some classes, these laws are taught by having the students memorize the words, instead of lecturing students or children about these somewhat complex laws. Here are a few ways to demonstrate the laws and gain a better understanding.
Newton's First Law of Motion
Place the hard boiled egg on its side and spin it. Put your finger on it gently while it is still spinning in order to stop it. Remove your finger when it stops.
Place the raw egg on its side and spin it. Place your finger gently on the egg until it stops. Once you remove your finger, the egg should start to spin again. The liquid inside the egg has not stopped so it will continue to spin until enough force is applied.
Push an empty shopping cart and stop it. Then push a loaded shopping cart and stop it. It takes more effort to push the loaded cart than an empty one.
Newton's Second Law of Motion
Drop a rock or marble and a wadded-up piece of paper at the same time. They fall at the same rate of speed, but the rock's mass is greater so it hits with greater force.
Push the roller skates or toy cars at the same time.
Push one harder than the other. One had greater force applied to it so it moves faster.
Newton's Third Law of Motion
- Hard boiled egg
- Raw egg
- Shopping cart
- Roller skates/toy cars
- Steel balls on a suspended frame/swing
Pull one ball or swing back and let it go.
It will swing into the other balls making the ball at the other end swing.
Explain how this represents an equal and opposite reaction.