Newton's Laws Of Motion
Newton's First Law
An object at rest stays at rest unless acted upon by an outside force; an object in motion stays in motion and travels at the same velocity unless acted upon by an outside force
For example, the blue marble on the right is at rest until another marble collides with it. The marble is now in motion because of the outside force (second marble.)
The red marble on the right is in motion until it ran into another red marble and stopped moving. The marble is now at rest because of the outside force (second marble.)
Newton's Second Law
The force is determined by the mass and acceleration of an object. To calculate the force of an object, take the mass and multiply it by the speed of acceleration. This should give you the force (in Newtons) of the object.
Suppose you are moving and you have to push a box out the door. You are curious and want to find how much force it takes for you to successfully move the box. You would first have to calculate the mass of the box. After you have done that, you would need to find out how long it takes for you to arrive at the door and how far you traveled (acceleration.) Multiply the mass of the box times the acceleration. This is how much force you exerted to push the box.
Newton's Third Law
Newton balls (right) are a perfect example on how this law works. If you lift up one ball and let go to let it collide with the next, the last ball at the end swings up in the same height you lifted the first one. "For every action there is an equal but opposite reaction." The Newton ball dropped and the last one swung up (opposite reaction,) but they both ended up being at the same height (equal reaction.)