Physics

Force

A push, pull or twist that can change an object's motion.

Newton (N)

The unit used to measure force.

Balanced Force

Forces that are equal in size but opposite in direction; do not cause changes in motion.

Unbalanced Force

Forces that cause changes in motion of an object.

Contact Force

A force that acts when two surfaces touch.

Non-contact Force

Forces that act at a distance from objects.

Gravity

The force that pulls an object toward the center of any mass or the center of the Earth.

Mass

The amount of matter in an object, measured in grams or kilograms.

Weight

A measure of how much gravity is pulling on an object, measured in newtons.

Net Force

The sum of all forces acting on an object.

Frictional Force

The force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

Air Resistance

A resistive force due to air that acts against motion.

Electrostatic Force

The force between two objects caused by a build-up of negative charges.

Magnetic Force

The attraction or repulsion force on an object caused by the buildup of magnetic charges.

Free Body Diagram

A diagram used to show all forces acting on an object.

Six Effects of Force

1. Making a stationary object move 2. Changing the speed of a moving object 3. Stopping a moving object 4. Changing the direction of a moving object 5. Changing the shape or size of an object 6. Transferring energy.

Like charges

like charges will repel and unlike will atract