# Simple Machines - PowerPoint PPT Presentation

Simple Machines

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Simple Machines

## Simple Machines

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##### Presentation Transcript

1. Simple Machines Enter

2. Inclined Planes Levers Pulleys Wedges Test Compound Machines Screws Wheels & Axles Glossary

3. Lever A lever can lift or move loads. Examples: see-saw, claw hammer, crow bar, bottle opener, piano keys, fishing rod, nutcracker. The point of support on which a lever turns on is called a fulcrum. Test See Examples

4. Fast Fact! It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighing more than 100 tons.

5. Pulleys A pulley can make lifting a load easier. A pulley consists of a wheel or set of wheels over which a rope, belt or chain can be pulled to raise or lower a load. Pulleys might be used to raise or lower a flag, window blind, sails on a ship, an object being lifted by a crane or to lift an engine from a car. Test See Examples

6. Fast Fact! The pulley system was invented by Archimedes, an ancient astronomer, inventor and mathematician who was born in 287 BC in Syracuse, Sicily. Archimedes also discovered the laws of levers and developed many of the basic principles of math and science.

7. Screws A screw is actually an inclined plane wrapped around a cylinder. Some screws are used to raise and lower things. Some are used to hold things together. You might find screws as part of bottles and jars and their lids, light bulbs, a vice, a jack, a wrench, as an auger ( to raise grain into a silo) and even a spiral staircase! Test See Examples

8. Fast Fact! Early screws were made from wood and were used in wine presses, olive oil presses, and for pressing clothes

9. Wheels and axles A wheel with an axle or cylinder through its centre can lift and move loads. A wheel and axle is often used with gears, which are wheels with cogs around the edge. A door knob is a simple wheel and axle. Other examples include a steering wheel, wagon wheels, car, a ferriswheel, gears in watches, clocks and bicycles. Test See Examples

10. Fast Fact! The wheel and axle was first invented in the Bronze Age.

11. Wedges A single wedge has a sloped surface. A double wedge has two sloping surfaces. Examples include doorstop, kitchen knife, fork, scissor blade, shovel edge, a nail, teeth, axe. A wedge can be used to push two objects apart or to split an object. Test See Examples

12. Fast Fact! The wedge tailed eagle is called the wedge tailed eagle because of its wedged tail.

13. An inclined plane is a flat surface which is higher on one end. Examples: wheelchair ramp, slanted road, stairs, a sloped path, slippery dip, escalators, boat ramp, ski jumps, skate ramps, base of a bathtub and the base of a wheelbarrow. It is easier to walk up a long, gentle pathway around a hill than to walk straight up it. Inclined Planes Test See Examples

14. Fast Fact! Our school visited the Katoomba Scenic Railway, which has the steepest slope of any railway.

15. A compound machine is made up of two or more simple machines working together as one, for example, a shovel handle is a lever and the blade is a wedge. A corkscrew is made up of levers, wheels and axles and a screw. Cars and aeroplanes, which are complex machines, are also based on the six simple machines. Compound and Complex Machines Test See Examples

16. These are some great examples of compound machines.

17. Glossary Cylinder: a hollow or solid body, shaped like a roller. Load: the weight to be supported or moved. Complex: something harder, or made with smaller things. Cog: a tooth on the edge of the wheel. Fulcrum: a support on which the lever turns. Device: a mechanical invention used for a special purpose.

18. Can You Identify these Simple and Complex Machines?