machine
A device with moving parts that work together to accomplish a task
input
Forces, energy, or power supplied to make a machine accomplish a task
output
Forces, energy, or power provided by a machine
simple machine
An unpowered mechanical device that accomplishes a task with only one movement
lever
A stiff structure that rotates around a fixed point called a fulcrum
gear
A rotating wheel with teeth that transfers motion and forces to other gears or objects
mechanical advantage
Ratio of output force to input force for a simple machine
work
A form of energy that comes from force applied over a distance
energy
A quantity that describes the ability of an object to change or cause changes
joule
A unit of energy. One joule is enough energy to push with a force of 1 newton for a distance of 1 meter
mechanical energy
A form of energy that is related to motion or position
chemical energy
A form of potential energy that is stored in molecules
nuclear energy
A form of energy that is stored in the nuclei of atoms
radiant energy
A form of energy that is represented by the electromagnetic spectrum
potential energy
Energy due to position
kinetic energy
Energy of motion
law of conservation of energy
Energy can never be created or destroyed, only transformed into another form. The total amount of energy in the universe is constant
work input
The work that is done on an object
work output
The work that an object does as a result of work input
efficiency
The ratio of usable output work divided by the total input work. Efficiency is often expressed as a percent, with a perfect machine having 100 percent efficiency.
power
The rate of doing work or moving energy. Power is equal to energy (or work) divided by time.
watt
A unit of power is equal to 1 joule per second
horsepower
A unit of power equal to 746 watts