Newton’s Laws of Motion

Sir Isaac Newton was a famous mathematician and scientist in the 1600’s.

This is the way most people remember him.

When most people think of Isaac Newton, they think of him sitting under an apple tree observing an apple fall to the ground. When he saw the apple fall, Newton began to think about a specific kind of motion—gravity.

Isaac Newton also understood other ways objects move Isaac Newton also understood other ways objects move. He came up with 3 rules or laws.

Newton’s 1st Law of Motion The First Law states that an object that is not being pushed or pulled by some force will stay still, or will keep moving in a straight line at a steady speed. This law is often called "the law of inertia". Inertia means that all objects resist any change in motion. This is why people wear seat belts. Without a seat belt your body keeps moving when the car stops.

Newton’s 1st Law of Motion This is why a rocket ship can keep going through space without a motor after blast off.

Newton’s 1st Law of Motion This is why you can pull the tablecloth out from under the dishes without the dishes moving. The dishes will remain at rest unless they are pushed or pulled.

Newton’s 1st Law of Motion This is why Sean was able to hit one penny from the middle of the stack without the others moving. (An object will stay still unless a force gives it a push or pull.)

This is also why if the same force is applied to two objects, one with more mass, the object with the greater mass will be harder to move. Objects with smaller mass have less inertia.

Newton’s 2nd Law of Motion The Second Law explains how a force acts on an object. Here are the rules:

Newton’s 2nd Law of Motion in More Detail An object accelerates in the direction the force is moving it.

Newton’s 2nd Law of Motion in More Detail The harder the force behind the push the faster the object will move.

Everyone knows that heavier objects require more force to move the same distance as lighter objects.                                                                                                                               

truck 1 truck 2 If both truck 1 and truck 2 are traveling at the same speed and apply brakes with the same force, truck 2 will take longer to stop because it has more mass. With more mass the truck has a greater push.

Newton’s 3rd Law of Motion The Third Law states that if an object is pushed or pulled, it will push or pull equally in the opposite direction. When this boy hits the pool, he is pushing into the water. An equal but opposite force will be a big splash.

http://www.bbc.co.uk/schools/scienceclips/ages/6_7/forces_movement_fs.shtml http://teachertech.rice.edu/Participants/louviere/Newton/law3.html

Experiments http://www.sciencespot.net/Media/newtonlab.pdf