Newton’s Laws of Motion Law of Inertia F=ma Action-Reaction

Many people have heard of Newton's Three Laws of Motion but not many people know what they are, or more importantly what they mean.

Let’s start with the basic definitions.. 1st law-An object at rest will stay at rest, and an object in motion will stay in motion at constant velocity, unless acted upon by an unbalanced force. 2nd Law-Force is equal to the mass times the acceleration. (F=ma) 3rd Law-For every action, there is an equal and opposite reaction.

Newtons First Law (Law of Inertia) This law states that an object, at rest or moving, will continue that action until stopped or moved by any force greater than its own. This carton of ice cream will stay on that counter FOREVER until acted upon by any force. Maybe it’s someone picking it up to eat or a tornado of cats knocks it off the shelf.

First law If something is airborne, it will stay moving until acted upon by a force. (On Earth this force will most likely be gravity. ) This baseball will stay in the air until a force acts on it. It would most likely be gravity, but who knows, maybe God wanted to push it back down for that centerfielder to make the winning out.

What is Inertia? Inertia is defined as the tendency of a body to resist acceleration, remain at rest if at rest, the tendency of a body in straight line motion to stay in motion in a straight line unless acted on by an outside force. This is stated in the first law.

How Newton’s First Law relates to you When riding in a car, you body experiences inertia. If you are traveling at 50 MPH and a deer runs out in the road, you must hit the brakes to avoid hitting it. Although the car is decelerating your body wants to continue moving at 50 MPH that’s why you feel the jerk forward.

F=mxa Newton’s Second Law 6 kg 4 kg F=(4kg)(9.81m/s/s) (9.81m/s/s) F=39 N (9.81m/s/s) F=(6kg)(9.81m/s/s) F=59 N Newton’s second law proves that different mass accelerate to the Earth at the same rate but with different forces.

Doubling the acceleration, doubles the force that it will have when landing on the Earth. On the other hand, doubling the mass, halves the acceleration.

How Newton’s Second Law relates to you The faster we move the more we produce. Much like school or careers, the more we learn and the quicker we do it, more force and power comes out of it. Getting good grades will give you more force and power to do what you want in life.

Newton’s Third Law For every action, there is an equal and opposite reaction. = What comes around goes around.

3rd Law Explanation The amount of force that the monkey is exerting down on the ground is exactly equal to the force that the ground exerts back up on the monkey. This keeps the monkey in place from going up or down. The gravity is exactly equal to the normal force of the ground.

Birds depend on Newton's Third Law Birds depend on Newton's Third Law. When the bird’s wings push down through the air, the air pushed back up into the wings with the same amount of force giving the bird the boost it needs to fly

How Newton’s Third Law relates to you When you walk from room to room in school, you are pushing down on the floor with a certain amount of force. In response to this, the floor pushes back up onto you with the same amount of force you’re exerting onto the floor. Without this equilibrium of force, we would either float around or sink through the ground.

Another thought.. Have you ever heard the saying “Treat others the way you want to be treated.” Or “What comes around goes around.” This is a very easy way to look at this law. Whatever you do, physical or not, there will ALWAYS be a reaction to your action. Think about moving furniture. When you push a desk, it will push back on your hand with the exact same amount of force that you are pushing on it.