# Newton's Law

## Newton's First Law of Motion

Newton’s first law states that every object will remain at rest unless an external force is acts on it. A force is a push or pull. This can also be taken as inertia. Inertia is the resistance of any object to a change of motion.If there is no net force acting on an object, then the object will maintain a constant velocity.If the velocity is zero then the object stays at rest. Newton’s first law of motion is commonly experienced when riding in cars and trucks.For example,if a ladder is strapped to the top of a truck, while the truck is moving the ladder would be to.As the truck accelerates, the ladder accelerates with it; as the truck slows down, the ladder decelerates with it. If the strap is no longer on,the ladder is more likely to maintain it’s state of motion. If the truck were to stop and there were no straps, then the ladder in motion would continue in motion.The ladder would slide off of the truck and be hurled into the air.

## Newton's First Law of Motion Picture

If a car would collide with a wall then upon contact an unbalanced force would act on the car to bring it to a rest.Any passengers in the car will also be decelerated to a rest.As the car speeds up,the passengers accelerate with it; as the car decelerates, the passengers decelrate with it.If the passengers were not wearing a seat belt and the car came to a sudden stop by the collision with a wall then, the passengers would no longer share the same state of motion as the car. The passengers in motion would stay in motion.

## Newton's Second Law of Motion

The second law states that the acceleration of an object is dependent on the net force acting upon the object and the mass of the object. As the force acting on an object is increased, the acceleration is increased. As the mass of an object is increased, the acceleration is decreased.The equation for Newton’s second law is f=ma (force=mass x acceleration). Mass is the amount of matter in an object and acceleration is the change of an object’s velocity during a given amount of time. If you multiply the mass times the acceleration of an object you get the force that object is exerting. An example of this being applied in real life would be a person who was trying to push their car after it ran out of gas. You would have to find the force that would be needed to push the car to the nearest gas station.If you were only moving your car about 0.05 meters per second, and the car weighed a total of 1,000 kilograms then you would have to plug these two numbers into the equation to see how much force you were exerting on the car.

## Newton's Second Law of Motion Picture

Newton’s second law means that the heavier an object is, the harder it has to be acted upon to make it move.This is shown in this picture.Even though both boys are using the same force and the same mass,the bigger rock is harder to move because it has a greater mass than the small rock.

## Newton's Third Law of Motion

Newton’s third law of motion states that for every action, there is an equal and opposite reaction.The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite action-reaction force pairs.Consider the flying motion of birds. A bird flies by use of its wings. The wings of a bird push air downwards. Since forces result from mutual interactions, the air must also be pushing the bird upwards. The size of the force on the air equals the size of the force on the bird; the direction of the force on the air (downwards) is opposite the direction of the force on the bird (upwards). For every action, there is an equal and opposite reaction. Action-reaction force pairs make it possible for birds to fly.

## Newton's Third Law of Motion Picture

While driving down the road, a firefly strikes the windshield of a bus and makes a quite obvious mess in front of the face of the driver. This is a clear case of Newton's third law of motion. The firefly hit the bus and the bus hits the firefly.Each force is the same size. For every action, there is an equal reaction. The fact that the firefly splatters only means that with its smaller mass, it is less able to withstand the larger acceleration resulting from the interaction.