Newton's Law of Motion

Newton’s First Law of Motion

Every object continues in its state of rest, or a uniform speed in a straight line, unless acted on by a nonzero force.

An object at rest tends to remain at rest; an object in motion tends to remain in motion at constant speed along a straight-line path.

Newton’s Second Law of Motion

The acceleration produced by a net force on an object is directly proportional to the net force, is in the same direction as the net force, and is inversely proportional to the mass of the object.

When a net force acts on an object, the object will accelerate.The acceleration is directly proportional to the net force and inversely proportional to the mass.

Acceleration=

Net Force/Mass

Free Fall

When the force of gravity is the only force—that is, when air resistance is negligible

Motion under the influence of gravitational pull only.

Air Resistance

The force of friction acting between an object and the surrounding air, depends on two quantities: speed and surface area

Terminal Speed

The speed at which the acceleration of a filling object terminates when air resistance balances weight.

Terminal Velocity

The maximum constant speed an object reaches while falling through a fluid, such as air

Interaction

Mutual action between objects during which one object exerts an equal and opposite Force on the other objects.

Newton’s third Law of Motion

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

When one object exerts a force on a second object, the second object exefrts an equal and opposite force on the first.

Newton’s third law is when

Implies at the same time.

Vector Quantity

A quantity whose description requires both magnitude and direction.

Scalar Quantity

A quantity, such as mass, volume, speed, and time, that can be completely specified by its magnitude.

Vector 

An arrow whose length represents the magnitude of a quantity and whose direction represents the direction of the quantity

Resultant

The net result of a combination of two or more vectors

Force Vector

An arrow drawn to scale so that its length represents the magnitude of the Force and its direction represents the direction of the force

Inertia 

The property of objects to resist change in motion

Acceleration 

Directly proportional to the net force and inversely proportional to the mass.

General Relativity

Objects under the influence of very strong gravitational forces:

Special Relativity

The relationship between space and time.

Quantum Mechanics

How atoms, electrons, photons, and other subatomic particles behave

Component

Mutually perpendicular vectors, usually horizontal and vertical, whose vector sum is a given vector.