Place a hard-boiled egg on its side and start it spinning with your hand. Let it continue to spin for a few seconds and then gently stop it with your fingers. Remove your hand immediately after the egg has stopped spinning. The hard-boiled egg will remain motionless. You have acted as an outside force and removed energy from the egg. This demonstrates part of the first law of motion that an object in motion will stay in motion unless acted upon.
Place an uncooked egg on its side and gently spin it, just as you did with the hard-boiled egg. Arrest its spin with your hand. Immediately remove your fingers from the egg. This time the egg will start to turn again. This happens because the liquid in the egg is still moving. You removed the energy from the shell, but not from the yolk and white that form the egg's interior. This demonstrates that an object at rest will stay at rest and an object in motion will stay in motion unless acted upon by an unbalanced force.
Pour flour into a metal pan until it is roughly one half-inch from the top. Take a marble in one hand and a gumball in the other and hold them above the metal pan full of flour. Drop them into the flour at the same time. You can drop them from any height, but the results will be more dramatic the higher the distance from which they are dropped. The marble and the gumball fell at the same speed, but had different results on the flour. The marble left a bigger crater than the gumball because the marble has more mass than the gumball. This demonstrates the second law of motion that force is equal to mass times acceleration.
Inflate a long, thin balloon. Do not tie it closed. Put a clothespin over the end to stop the air from escaping.
Insert string into a drinking straw and push it all the way through so that there is string hanging out of both ends. Tape the balloon to the straw so that both are pointing in the same direction. Tape each end of the string to opposite walls. An alternative is to have two people hold the ends of the string. In either case, the string must be taut.
Slide the balloon along the string until it reaches the wall or the hand of the person holding it. Place the nozzle end closest to the wall. Remove the clothespin and the balloon rocket will fly along the string. This demonstrates the third law of motion that for every action there is always an opposite and equal reaction.