# Simple Machines and Mechanical Advantage

## Presentation on theme: "Simple Machines and Mechanical Advantage"— Presentation transcript:

What is a Machine? Definition:
any device that makes work easier by changing a force Work is done whenever a force moves an object over a distance

How do machines make work easier?
Machines change how the work is done by Increasing the amount of force that is applied Increasing the distance over which the force is applied Changing the direction in which the force is applied

Increasing force? The machine applies more force than the user but over a shorter distance

Increasing Distance The machine increases the distance over which the force is applied, but it reduces the strength of the force

Changing the direction of force
The machine changes the direction of the force applied by the user

Simple vs. Compound Machines
There are 6 types of simple machines Inclined plane Lever Pulley Wheel and Axle Screw Wedge Compound machines combine two or more simple machines

Measuring the change in force
How much a machine changes the input force is called its mechanical advantage Remember Input force = force you place on machine Output force = force machine places on object Two types: Actual Ideal

Takes into account the amount of the input force that is used to overcome friction Difficult to measure input and output forces

Uses input and output distance instead of force Does not take into account friction and will always be greater than actual mechanical advantage

Practice Calculate the ideal mechanical advantage for the incline plane shown above.

Practice A force of 200 N is applied to a machine in order to lift a 1,000 N load. What is the mechanical advantage of the machine? A machine is designed to push an object with a weight of 12N. If the input force for the machine is set at 4 N, what is the mechanical advantage of the machine?

Practice An input force of 35 N is applied to a machine with a mechanical advantage of What is the size of the load this machine could lift (how large is the output force)? A machine is required to produce an output force of 600 N. If the machine has a mechanical advantage of 6, what input force must be applied to the machine?