Section 2Work and Energy EQ: How are work and mechanical advantage of simple machines calculated?

Section 2Work and Energy What Are Simple Machines? What are the six types of simple machines?

Section 2Work and Energy What Are Simple Machines? The six types of simple machines are the simple lever, the pulley, the wheel and axle, the simple inclined plane, the wedge, and the screw.

Section 2Work and Energy What Are Simple Machines?, continued Lever family: –simple lever –pulley –wheel and axle Inclined plane family: –simple inclined plane –wedge –screw

Section 2Work and Energy The Lever Family What are the two principal parts of all levers?

Section 2Work and Energy The Lever Family All levers have a rigid arm that turns around a point called the fulcrum.

Section 2Work and Energy The Lever Family First class lever: fulcrum is between the input force and the output force Ex. hammer

Section 2Work and Energy The Lever Family Second class lever: output force is between the input force and the fulcrum Ex. Wheel barrow

Section 2Work and Energy The Lever Family Third class lever: input force is between the output force and the fulcrum 〉 Ex. arm

Section 2Work and Energy The Lever Family, continued

Section 2Work and Energy The Lever Family, continued The point in the middle of a pulley is like the fulcrum of a lever and the rest of the pulley behaves like the rigid arm of a first-class lever.

Section 2Work and Energy The Lever Family, continued A wheel and axle is a lever or pulley connected to a shaft. Ex. Screwdrivers and cranks

Section 2Work and Energy The Lever Family, continued A pulley system’s MA can be determined by counting the number of ropes supporting the load.

Section 2Work and Energy The Mechanical Advantage of Pulleys

Section 2Work and Energy The Inclined Plane Family How does using an inclined plane change the force required to do work?

Section 2Work and Energy The Inclined Plane Family Pushing an object up an inclined plane requires less input force than lifting the same object does.

Section 2Work and Energy The Inclined Plane Family A wedge is a modified inclined plane.

Section 2Work and Energy The Inclined Plane Family A screw is an inclined plane wrapped around a cylinder.

Section 2Work and Energy Compound Machines What simple machines make up a pair of scissors?

Section 2Work and Energy Compound Machines A pair of scissors uses two first-class levers joined at a common fulcrum; each lever arm has a wedge that cuts into the paper.

Section 2Work and Energy Compound Machines compound machine: a machine made of more than one simple machine