1 / 21

# Simple Machines - PowerPoint PPT Presentation

Simple Machines. Essential Questions. What is the purpose of the simple machines?. Simple Machine Types. There are 6 basic kinds of simple machines. These are: Inclined Plane Wedge Screw Levers Wheel and Axle Pulley. Inclined Plane. An inclined plane is a flat, slanted surface.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about ' Simple Machines' - zora

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Simple Machines

• What is the purpose of the simple machines?

• There are 6 basic kinds of simple machines.

• These are:

Inclined Plane

Wedge

Screw

Levers

Wheel and Axle

Pulley

• An inclined plane is a flat, slanted surface.

• An example of an inclined plane is a ramp.

• The longer the inclined plane, the less input force you need to push or pull an object.

• Even though an inclined plane has no moving parts, work is lost due to friction.

• This is because friction comes from the bottom of the box rubbing against the ramp.

• A wedge is a device that is thick at one end and tapers to a thin edge at the other end. A wedge is used to cut through an object.

• You can think of a wedge as an inclined plane that moves.

• The longer and thinner the wedge is, the less input force is required.

• An example of a wedge is: an axe, a knife, a screwdriver, boat.

• A screw can be thought of as an inclined plane wrapped around a cylinder.

• An example of a screw is a jar lid, a bolt, and a faucet.

• A lever is a rigid bar that is free to pivot or rotate around a fixed point.

• The fixed point that a lever pivots around is called the fulcrum.

• There are 3 classes of levers.

• First class levers have the fulcrum located between the input force and output force.

• For example, scissors, seesaw, and pliers are first-class levers.

• Second-class levers have the fulcrum located closer to the output force.

• Examples of second-class levers are nutcrackers, doors, bottle openers, and wheelbarrows.

• Third-class levers have the fulcrum located closer to the input force.

• Examples of third-class levers are fishing poles, shovels, and baseball bats.

• BrainPop Video

• A wheel and axle is a simple machine made of 2 circular or cylindrical objects (wheels)that are fastened together and rotate around a common object (axle).

• The larger object is called the wheel and the smaller object is called the axle.

• An example of a wheel and axle is a screwdriver, door knob, or steering wheel.

• BrainPOP video

• A pulley is a grooved wheel with a rope wrapped around it.

• You use a pulley by pulling on the rope.

• A pulley that you attach to a structure is called a fixed pulley.

• If you attach a pulley to the object you wish to move, then you are using a movable pulley.

• If you combine fixed and movable pulleys, you can make a pulley system.

• A machine that utilizes two or more simple machines is called compound machine.

• Examples are: bicycle, pencil sharpener, bulldozer.

• Gears form a compound machine with one wheel and axle linked to another wheel and axle.

• What machine works with gears? Bicycle

• How does a doorknob work?

The knob is a wheel and the axle pulls in the closer so the door will open.

• What on a lever does not move?

Fulcrum

• How are wedges and screws related?

Both have inclined planes.

• What are three ways in which a machine can make work easier?

By changing the force, distance, or direction

• How can you determine if work is done on an object?

Work is done when an object moves.