15 terms

# Unit 2 Work, Energy and Machines

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work
The use of force to move an object some distance in the direction of the force.
equation for work
W = F x d
work = force x distance
energy
is the ability to do work
power
is the rate at which work is done
equation for power
P = E/ t
power = energy divided by time
joule
standard unit of measurement for both work and energy
watt
is the standard unit of measurement for power
potential energy
is the energy an object has because of its position, condition or chemical composition
kinetic energy
is the energy of motion
equation for kinetic energy
KE = 1/2mv2
kinetic energy = 1/2 mass x velocity squared
elastic potential energy
is stored in a stretched spring or rubber band
chemical potential energy
a substance stores energy as a result of its chemical bonds
gravitational potential energy
is due to its position above the ground
machine
any device that helps people do work
six types of simple machines
levers, wheels and axles, pulleys, inclined planes, wedges and screws