Newton's Laws of Motion

By: Madelyn Peterson

Newton's Law of Inertia

This is the first law of motion that states that an object in motion will stay in motion and an object at rest will stay at rest unless they are acted upon by an unbalanced force. Inertia is the tendency of an object to resist change in motion. An example would be a car driving down a highway and coming to a complete and sudden stop. The people and objects in the car will want to resist change they will continue to move unless stopped by an unbalanced force (a.k.a. the seatbelt). Another example would be a person on a bike. In order for the bike to start moving it has to be acted on by an unbalanced force to overcome it's tendency to stay in rest. In this situation the unbalanced force is the person pushing the pedals.

Newton's Law of Force and Acceleration

This is the second law of motion and states that the acceleration of an object depends of the mass of the object and the net force applied. Acceleration is the rate at which velocity changes over time. For example, an adult can lift a heavy object whereas an infant can't because they have stronger muscles that can exert the force needed to lift the mass of that object. Another example would be pressing on piano keys. If the mass of the key or resistance is great then you need to apply more force to the key for it to move so the hammer can strike the string to make the note sound.

Newton's Law of Action/Reaction

This is the third law that states when one object applies force on a second object, the second object applies an equal and opposite force to the first. An example of this is a person sitting in a chair. The person is applying force to the chair when sitting on it, and the chair is pushing with an equal amount of force back at the person making them together a balanced force. Although you cannot see the force the chair is pushing back with, the person would be unable to sit and stay in the chair without it. Another example of this law is a balloon. The air is released out of the balloon, and the balloon pushes up with the same amount of force in the opposite direction.