What is a machine

mechanical advantage

a number that tells how many times a machine multiplies force

machines

Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work.

How machines make it easier

Machines make work easier by changing the size or direction

Force distance trade off

When a machine changes the size of the force, the distance through which the force is exerted must also change. Force or distance can increase, but both cannot increase. When one increases, the other must decrease.

machine

a device that helps do work by either overcoming a force or changing the direction of the applied force

everyday machines

a knife, Wheelchair, scissors, chopsticks, ect...

mechanical effencity

a quantity, usually expressed as a percentage, that measures the ratio of work output to work input in a machine

screw driver example

the screwdriver does not do more work on the lid than you do on the screwdriver.

work output

the work done by a machine; the product of the output force and the distance through which the force is exerted

work input

the work done on a machine; the product of the input force and the distance through which the force is exerted