Sir Newton's Laws of Motion

What is Newton's first law of motion?

Law 5   Every body continues in its state of rest or of uniform speed in a straight line unless acted on by a nonzero net force.

This profound law has its roots in Aristotelian and Galilean work and explains why objects begin to move, stay in motion or remain at rest.

How does Newton's first law of motion relate to inertia?

Intimately: Inertia is the tendency for a body to maintain its current state of motion (or lack thereof) and Newton's first law is also referred to as the Law of inertia.

What is Newton's second law of motion?

Law 6   The acceleration of an object is directly proportional to the net force acting on it and is inversely proportional to its mass. Further, the direction of acceleration is in the direction of the net force acting on the object.

In Newton's second law of motion, $F$ is the force in Newtons (N), $m$ is the mass in kilograms (kg) and $a$ is the acceleration in ${m}/{s^{2}}$:

$$\Sigma F = ma$$ (61.1)

Assuming the force applied and the mass of the object is constant, then the acceleration of the object is directly proportional to the force applied (e.g. twice the force results in twice the acceleration) and inversely proportional to the mass of the object (e.g. twice the mass results in half the acceleration).

Based on Newton's second law of motion what is a force?

An action capable of accelerating an object.

What is Newton's third law of motion?

Law 7   Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

$$F_{A \rightarrow B} = - F_{B \rightarrow A}$$ (61.2)

Or, for every action, there is an equal and opposite reaction as seen in Equation 60.2 above.

What is the day-to-day application of Newton's third law of motion?

Newton's third laws explains why motion occurs. For example, if you are in a dingy next to a dock; when you push against the dock with a certain force, the dock exerts an equal force on to you and the dingy. Because the force you applied is on to a massive dock that has been secured with many pilings, its movement is imperceivable (albeit still occurs). You, on the other hand, are in a dingy floating on a relatively frictionless surface and your movement will be pretty apparent.