Agenda for 5/13/16 Simple Machines Notes Classes of Levers worksheet HW – None TEST WEDNESDAY!

What is a Simple Machine? Machine - a tool that helps us do work A simple machine - has few or no moving parts.

Machines help us by: Changing the amount of force on an object. Changing the direction of the force.

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

1) Inclined Planes An inclined plane – a slanted surface to make lifting easier Ex. Ramp, stairs A sloping surface, such as a ramp. An inclined plane can be used to alter the effort and distance involved in doing work, such as lifting loads. The trade-off is that an object must be moved a longer distance than if it was lifted straight up, but less force is needed. You can use this machine to move an object to a lower or higher place.  Inclined planes make the work of moving things easier.  You would need less energy and force to move objects with an inclined plane. 

2) Wedges Wedge - two inclined planes together used to raise an object or split an object Ex. Knife, door wedge, axe, teeth

3) Screws A screw is an inclined plane wrapped around a pole that is used to hold materials together or drill holes Ex. Drill bit, screws, lid of a PB jar, light bulb

4) Wheels and Axles Wheel and Axle – a wheel that turns on a post to help move things quickly and easily Wheel and axle work together Ex. Steering wheel, doorknob, screwdriver Gears are a form of wheels and axles

5) Pulleys Pulley – a grooved wheel with rope, chain, or cable running along the groove Can change direction of a force Ex. Flagpole, clothesline, crane, fishing reel

Diagrams of Pulleys Fixed pulley: Movable Pulley: A fixed pulley changes the direction of a force; however, it does not create a mechanical advantage. Movable Pulley: A movable pulley – a pulley in which one end of a rope is fixed and the wheel is free to move; increases the force

6) Levers Lever – a bar that is free to pivot or turn around a fixed point The fixed point is called a fulcrum Can be used to lift weight Ex. Seesaw, crowbar, baseball bat, rake

Levers-First Class First class lever - the fulcrum is in the middle and the load and effort is on either side Think of a see-saw

Levers-Second Class Second class lever - the fulcrum is at the end, with the load in the middle Think of a wheelbarrow

Levers-Third Class Third class lever - the fulcrum is again at the end, but the effort is in the middle Think of a pair of tweezers

Which Simple Machine? Hammer Wrench Wedge Wheel and Axle 1st Class Lever

Which Simple Machine? Flag and Pole Screwdriver Pulley Wedge, lever, wheel and axle

Which Simple Machine? Staples Paint roller Wedge Wheel and Axle

Which Simple Machine? Rope and pulley Paintbrush Pulley 2nd Class Lever

Which Simple Machine? Ratchet Doorknob Wheel and Axle Wheel and Axle

Which Simple Machine? Saw Light Bulb Screw Wedge

Compound Machines Compound Machine - two or more simple machines working together. Ex. Can Opener – The handles act as a lever, wedge pierces the can, and then crank the wheel and axle to open the can.

Rube Goldberg Machines Rube Goldberg machines are examples of compound machines. All compound machines are made up of combinations of simple machines. Rube Goldberg machines are usually a complicated combination of simple machines. By studying the components of Rube Goldberg machines, we learn more about simple machines

When you slip on ice, your foot kicks paddle (A), Safety Device for Walking on Icy Pavements When you slip on ice, your foot kicks paddle (A), lowering finger (B), snapping turtle (C) extends neck to bite finger, opening ice tongs (D) and dropping pillow (E), thus allowing you to fall on something soft.

Awesome Rube Goldberg machines http://www.youtube.com/watch?v=qybUFnY7Y8w http://www.youtube.com/watch?v=_ve4M4UsJQo

Agenda for 5/16/16 Classes of Levers worksheet Simple Machines Activity Simple Machines Review Sheet Work on Unit 7 Review Sheet HW– Finish Unit 7 Review Sheet TEST WEDNESDAY! http://www.youtube.com/watch?v=GOMIBdM6N7Q

Which Simple Machine? Scissors Seesaw Wedge 1st Class Lever

Which Simple Machine? Drill Bit Crowbar Wedge 1st Class Lever Screw

Which Simple Machine? Shovel Car Jack Wedge Wheel and Axle 3rd Class Lever

Which Simple Machine? Wheelbarrow Rake Wedge 3rd Class Lever Wheel and Axle 2nd Class Lever

Which Simple Machine? Forceps Pliers Wedge 1st Class Lever Wedge

Which Simple Machine? Wheelchair Putty Knife Wedge Wheel and Axle

Which Simple Machine? Ferris Wheel Wheel and Axle

Agenda for 5/16/11 Go over homework Go over Life Science Packets Work on Unit 7 Review Questions – whatever you don’t finish is homework Test on Wednesday