Force

Newton's First Law

An object at rest will stay at rest, and an object in motion will stay in motion with the same speed and direction unless acted upon by an unbalanced force.

Inertia

The tendency of an object to resist changes in its motion.

Mass and Inertia Relation

An object's inertia is based on its mass.

Greatest Inertia Example

A 15-kilogram object at rest has the greatest inertia.

Newton's Second Law

The acceleration of an object depends on the net force acting on it and the mass of the object.

Second Law Formula

F = ma, where F is force, m is mass, and a is acceleration.

Static Friction

The type of friction that prevents motion between two surfaces.

Kinetic Friction

Friction that occurs during motion.

Newton's Third Law

For every action force, there is an equal and opposite reaction force.

Weight

The force caused by gravity acting on mass, calculated as W = mg.

Net Force

The vector sum of all forces acting on an object.

Equilibrium

A state where the net force on an object equals zero.

Friction's Dependence

Friction depends on surface type and normal force, not surface area.

Components of Weight on an Incline

The weight has a parallel component (mg sinθ) causing sliding and a perpendicular component (mg cosθ) balanced by the normal force.

Centripetal Acceleration

Acceleration directed toward the center of a circular path.

Universal Gravitation

Every mass attracts every other mass with a gravitational force calculated by Fg = Gm1m2 / r².

Effect of Distance on Gravitational Force

The gravitational force decreases as the distance is squared.

Ff = μFn

The formula for the force of friction, where μ is the coefficient of friction and Fn is the normal force.

Effects of Mass on Acceleration

For the same force, lighter objects will accelerate more than heavier objects.

Normal Force on Incline

The normal force acts perpendicular to the inclined surface.

Condition for Sliding on an Incline

An object slides down when the parallel component of weight exceeds the friction force.

Impact of Force on Acceleration

If net force increases while mass remains constant, acceleration will increase.