mr. johnson perrysville junior high updated 2-3-2010

Mr. JohnsonPerrysville Junior High

Updated 2-3-2010

Terms To Know

Work – done when an applied force causes an object to move in the direction of the force

Energy – ability to cause change; speed, force, shape, or temperature

Load – weight being moved Effort - force placed on an object that cause it

to move.

What is a Simple Machine?

Tool used to make work easier

Few moving parts Increased mechanical

advantage Increase magnitude

of out put force w/ cost of increased distance moved

Inclined Plane

Inclined plane is a surface set at an angle, against a horizontal surface.

Use less force over a longer distance to raise an object

Object moves, not inclined plane

Wedge

Similar to “Inclined Plane”

Does work by moving

More acute the angle of the wedge, the more mechanical advantage it will have.

Screw

A screw is a helical inclined plane

A screw converts a rotational force, torque, into a linear force

Pulley

Used to change the direction of an applied force

Realize a mechanical advantage in either a linear or rotational system of motion.

Wheel and Axle

Wheel & axles multiply the applied force OR distance traveled.

Larger diameter wheels exert stronger forces on axles

1st Class Lever

fulcrum is located between the input effort and the output load

2nd Class Lever

fulcrum is at one end, and the applied force at the other, with the load in between

Load moves the same direction as the applied force

3rd Class Lever Input effort is higher

than the output load Applied force is

between fulcrum and load

Moves Faster