Physics: Work and Energy

Work

product of force and direction; W = Fd

Force

A push or pull exerted on an object

net work

the sum of the work done on an object by each force acting on the object

kinetic energy

the energy an object has due to its motion

potential energy

stored energy that results from the position or shape of an object

gravitational potential energy

Potential energy that depends on the height of an object

elastic potential energy

the energy of stretched or compressed objects

work-energy theorem

The work done by a net force on an object equals the change in kinetic energy of the object

change in kinetic energy

net work

kinetic energy formula

KE = 1/2mv^2 (^2 = squared)

acceleration due to gravity

the acceleration of an object in free fall that results from the influence of Earth's gravity

vertical displacement

height

gravitational potential energy formula

PEg = mgh

spring constant

(k) a measure of a spring's resistance to being compressed or stretched

elastic potential energy equation

PEe = 1/2 k x^2 (x squared) (x = distance compressed or stretched)

mechanical energy

sum of kinetic energy and all potential energy associated with an object

mechanical energy formula

ME = KE+ the sum of PE

conserved quantities

quantity remains constant; can change form over a period of time but the amount will always be the same

conservation of energy

Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes

friction

the resistance that one surface or object encounters when moving over another.

air resistance

force that opposes the motion of objects that move through the air

power

the rate at which work is done (P = W/t)

watt

A measure of power equal to one joule of work per second.

kilowatt

a unit of power equal to 1000 watts