Friction and Gravitational Interactions

Friction

A force that acts in a direction opposite to the motion of an object, eventually stopping it.

Types of Friction

There are four types of friction: rolling, sliding, fluid, and static.

Rolling Friction

Friction that occurs between two smooth surfaces, such as rolling on a skateboard.

Sliding Friction

Friction that slows down and stops moving objects.

Fluid Friction

Friction that occurs when a solid object moves through a fluid, such as water or air.

Static Friction

Friction that acts on objects when they are resting on a surface.

Gravity

A force that pulls objects toward each other, experienced through the attraction of objects toward the Earth's core.

Law of Universal Gravitation

States that the force of gravity acts between all objects in the universe that have mass.

Gravitational Force

Depends on the mass of each object and the distance between them.

Mass

A measure of the amount of matter in an object.

Weight

A measure of gravitational force on an object, with the SI unit being a newton (N).

Newton's Second Law

Net force = Mass x Acceleration.

Gravitational Potential Energy

Potential energy associated with the position of an object in a gravitational field, calculated as GPE = Mass x Acceleration due to gravity.

Air Resistance

A type of fluid friction that acts on objects moving through the air.