Work and Machines
Work is being done when you exert a force that moves an object in the direction of the force.
The unit for work is the Joule.
Power is how fast work is being done.
A ___ is a device that helps make work easier by changing the size or direction of a force. machine
Examples of machines include a pair of scissors, a screw, a bottle opener.
The work you do on a machine is called work input.
The work done by the machine is the work output.
A ___ is a simple machine consisting of a bar that pivots at a fixed point, called a fulcrum. lever
An ___ is a simple machine that is a straight, slanted surface. inclined plane
A ramp is an example of an inclined plane.
A ___ is a double inclined plane that moves. wedge
A zipper is made from three wedges.
A ___ is an inclined plane that is wrapped in a spiral. screw
A jar lid is an example of a screw.
A ___ is a simple machine consisting of two circular objects of different sizes. wheel and axle
A doorknob, wrench and Ferris wheel are examples of a wheel and axle.
A ___ is a simple machine consisting of a grooved wheel that holds a rope on a cable. pulley