Levers & Pulleys Investigations One & Two PowerPoint

Simple Machine – Any of the six devices (including levers and pulleys) that provide mechanical advantage.

The Six Simple Machines Video Clip (2:18)

Machine – A device that uses energy and does work.

What is a Machine? Video Clip (0:47)

Complex Machine – A machine that is designed using a number of simple machines, often run by a motor.

Complex Machines Video Clip (2:51)

Force – Energy, such as a push or a pull, that changes the motion or shape of an object.

Mechanical Advantage - A measure of how much a machine multiplies the effort force put into it.

Effort – The force applied to move a load using a simple machine.

Newton (N) - The metric unit used to measure force/effort.

6 Six Simple Machines Lever Family Lever Wheel and Axle Pulley Inclined Plane Family Inclined Plane Wedge Screw 6

Equal-arm Balance – A scale used to compare masses placed at equal distances from the fulcrum.

Building the Pyramids of Giza Video Clip (@4:00)

Archimedes’ Water Screw Vituvius’ Water Wheel

Archimedes – A Greek mathematician, engineer, and inventor who studied the way levers work.

Archimedes' Simple Machines Video Clip (1:56)

Lever - A bar that turns on a fixed point or fulcrum, that is used to move a load. (i.e. seesaw)

Lever Video Clip (1:14)

Lever Arm – The beam or bar of a lever that is free to pivot on a point.

Fulcrum – The point at which a lever arm pivots.

Load – The weight or resistance that is moved using a simple machine.

Effort – The force applied to move a load using a simple machine

The Three Main Parts of a Lever Video Clip (0:50)

In a lever, the closer the load is to the fulcrum the less effort it takes to lift the load. This mechanical advantage comes at a cost, you trade reduced effort for increased distance.

Double Lever – A machine that uses two levers working together.

Wheel and Axle – A wheel or bar that rotates around an axis.

The wheel and axle is sometimes known as a “lever in the round” or a “rotating lever”.

Wheel & Axle Video Clip (1:28)

Windlass – A wheel-and-axle system used to apply force to a rope while winding it around the axle. (a.k.a. a winch).

Wheels make it easier to move things along by reducing friction.

Pulley – A wheel with a groove through which a rope runs, that changes the direction of force or multiplies mechanical advantage.

Inclined Plane – A simple machine made of a flat, slanted surface, or ramp.

Wedge – A double inclined plane that tapers to a point or sharp edge.

Screw – An inclined plane wrapped around a center post, creating threads.

Two-coordinate graphs – show relationships between two variables. Levers Two-coordinate graphs – show relationships between two variables.

Advantage – Is a benefit obtained by using a lever (or other simple machine).

FLE 123 (Fulcrum) (Load) (Effort) (Class 1) (Class 2) (Class 3)

F 1 L 2 E 3

Class-1 Lever – A lever in which the fulcrum is between the load and the effort

Class-1 Lever Examples Include: a hammer, a crowbar, a shovel, and a teeter-totter.

Class-2 Lever – A lever in which the load is between the fulcrum and the effort.

Class-2 Lever Examples Include: a wheelbarrow, a paper cutter, a door, and a bottle opener.

Class-3 Lever – A lever in which the effort is between the fulcrum and the load.

Class-3 Lever Examples Include: a fishing pole, a baseball bat, a broom, and your arm.

The Three Classes of Levers Video Clip (2:20)

Plane – flat surface Inclined – sloped or at an angle Inclined Plane – A flat surface set at an angle, used to change the direction of a force.

An inclined plane spreads effort out over distance making the work “easier”. The longer the inclined plane, the less effort you need to move the load, but the load must move a greater distance.

Inclined Plane Video Clip (1:58)

An inclined plane? I think not.

More Leverage Diagram – A drawing that describes the relationship of all parts of a system.

Investigations One & Two Review Questions What is the term for the six devices that provide mechanical advantage? What is a machine? What is a complex machine? What is the term for energy that changes the motion or shape of an object? What is mechanical advantage? What is the force applied to move a load using a simple machine known as? Name all six simple machines? What is a Newton? What is the term for a bar that turns on fulcrum and moves a load? What is the term for a wheel or bar that rotates around an axis?

What is a pulley? Which simple machine is made of a flat, slanted surface? What is a wedge? What is the term for an inclined plane wrapped around a center post? What is an equal-arm balance? Who was Archimedes? What is a lever arm? What is the term for the point at which a lever arm pivots? What is a load? What is effort? In which type of lever is the fulcrum between the load and the effort? What are some examples of class-1 levers?

What fulcrum location gives you the most mechanical advantage in a lever? What is a double lever? Which simple machine is sometimes referred to as a “rotating lever”? What is a windlass? What do wheels help to reduce? In which type of lever is the load between the fulcrum and the effort? What are some examples of class-2 levers? In which type of lever is the effort between the fulcrum and the load? What are some examples of class-3 levers? What is the term for a flat surface set at an angle, used to change the direction of a force? How does an inclined plane make work “easier”?

THE END!