Advertisement Upgrade to remove ads


The use of energy to apply a force to move an object. Work is defined as the amount of force multiplied by the distance the object moves.


The standard SI unit of energy, which is the ability to do work. It is defined as the energy used by a force of one newton moving an object a distance of one meter.

simple machine

A device made up of one or two parts that reduces the effort neede to do work. It magnifies any applied force.


A rigid bar that picots about a fulcrum to multiply the force applied to one end.


A fixed point that a lever pivots at.

law of moments

For a lever with different amounts of weight on each side to be balanced, the distance that the first weight is from the pivot point multiplied by the weight, must equal the second weight multiplied by its distance from the pivot point. D(1)W(1)=D(2)W(2)


Torque is the turbning force acting on an object that is rotating or attached to a pivot point. It is the force multiplied by the distance of the force from the pivot point.

first-class lever

A type of lever where the fulcrum is between the effort force, and the resistance force.


The force that is being applied to a machine, to produce work.

effort arm

In a lever, it is the distance between the effort and the fulcrum.


The force from the weight of the object we are trying to move with a simple machine.

resistance arm

In a lever, it is the distance between the resistance and the fulcrum

mechanical advantage

The property by which a simple machine multiplies an input force.

second class lever

A type of lever where the resistance force is between the fulcrum and effot force.

third-class lever

A type of lever where the effort force is between the fulcrum and the resistance force.

wheel and axle

A simple machine that can be thought of as a lever that rotates in a circular manner aboutn and axle, which acts as a fulcrum.


A type of simple machine compesed of a rope wrapped around a wheel.

block and tackle

A system composed of two or more pulleys connected by ropes.

distance principle

Using mechanical advantage to reduce the force necessary to move something will result in an increase inthe distance that the force acts.

inclined plane

A simple machine that consists of a flat surface arranged at an angle so that one end is higher that the other.


A simple machine that has inclined planes on two sides, that come to a point.


A simple machine made of an inclined plane wrapped around a shaft.


1) the distance between the threads of a screw that determine its mechanicas advantage. 2) related to frequency, it is how high or how low our ears percieve a tone to be.


For a simple machine, it is output work divided by the input work.


It is the rate at which work is perfomed, which is work done per unit of time, measured in watts.


The standard SI unit for power, defined as 1 joule per second.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording