Warm-Up: Make a list of different objects that help to reduce the amount of force required to do work.

6-5.7 VOCAB Words: 1.Simple machine 2.Effort force 3.Lever 4.Fulcrum 5.Pulley 6.Moveable pulley 7.Single fixed pulley 8.Inclined Plane Write these 8 vocabulary words in your ISN on the left side.

Warm-Up: In a paragraph, explain how a lever (simple machine) helps reduce the amount of force required to do work.

1. What two factors are required for work to be done? a)Energy must be transferred; force must be used. b)Force must be applied; the object must be held c)Energy must be applied; a tool must be used. d)Force must be applied; the object must move. 2.Work is being done on an object in all of the following situations EXCEPT ___. a)student pulls a desk to the other side of the room. b)A girl holds the grocery bag for her mother. c)The children move their mats to the center of the room. d)A boy pushes his bicycle down the driveway. 3. How are work and energy related? a)Work does not use energy. b)Work requires more energy than force. c)All kinds of energy cause work to be done. d)If work is done, then energy is used. 4. In the picture, which object is doing the work on the nail? a)the hammer c) the board b)the naild) the hand

Warm-Up: Get your papers (2) out of the basket. Clear everything off of your desk except for your papers, ISN, and a pencil.

1. In which situation is work NOT being done? A. A mover pulls a large box to the other side of the room. B. A girl holds the grocery bag for her father. C. Students move their desks into a circle. D. A boy pushes the mower across the lawn. 2. Two men are pushing a box. They each push for 30 seconds but do not move the box. The men applied _____ but no _____ was done. A. force, work B. force, energy C. work, force D. pull, work 3. In order for work to be done on an object, what requirement has to be met? A. Force is applied. C. Force moves the object. B. Energy is used. D. The object is carried. Warm-Up:

Warm-Up For each statement below, identify whether or not work is being done by writing TRUE or FALSE. If the statement is FALSE, work not being done, then explain why work is not being done. 1.Morgan pulled the dog around the yard in her wagon all afternoon. 2. The marina lifted three boats out of the water yesterday before the storm arrived. 3. Debbie pushed the couch for 5 minutes, but she could not get it to move. 4. John moved the playhouse from the front yard to the back yard. 5. Amber tried to move the extra large plant to the back porch but could not get it to move.

Simple Machines Explain how the design of simple machines (including levers, pulleys, and inclined planes) helps reduce the amount of force required to do work Illustrate ways that simple machines exist in common tools and complex machines.

Simple machine – device that helps reduce the amount of force required to do work. Make work easier by: 1.allowing user to apply less force. 2.allowing user to apply a smaller force over a longer distance. 3.allowing user to change the direction of force applied There are six common simple machines.

Lever – rigid bar or board that is free to move around a fixed point called a fulcrum. Fulcrum may be placed at different locations along the bar.

Reduces amount of force required to lift a weight in two ways: (1)increasing distance from fulcrum to point where effort force is applied, or (2)decreasing distance weight is from fulcrum. By increasing distance effort force moves relative to distance weight moves, a lever can reduce effort force needed.

Fulcrum between, effort force and weight – Ex: scissors, crowbar, seesaw, shovel.

Fulcrum on end, effort applied in middle, to lift weight on other end – Ex: tweezers, broom, hammer.

Fulcrum on end, effort force applied on other end, to lift a weight in middle. – Ex: wheelbarrow, bottle opener, nutcracker.

Pulley – a grooved wheel with rope running along grove. Changes amount and/or direction of force applied. By arranging pulleys in such a way as to increase distance that effort force moves relative to distance weight moves, a pulley can reduce effort force needed.

Movable pulleys reduce effort force. Ex: construction cranes part of block and tackle system Single fixed pulley changes only direction of force (you pull down and weight goes up.) Fixed pulley (attached to structure) can be found on top of flag pole and on window blinds.

Inclined Plane – sloping surface that reduces amount of force required to lift object. – Ex: Ramps, stairs Designed to reduce force needed to lift a weight in two ways: (1)Increase length of ramp, or (2)Decrease height of ramp.

By increasing distance effort force moves (ramp length) relative to distance weight is lifted (ramp height), an inclined plane can reduce effort force needed.

Inclined Planes that are… Wedges – one inclined plane or two back-to-back inclined planes – Ex: knife blades, nails Screws – an inclined plane wrapped around a post or cylinder. – Ex: screws, bolts, jar lids.

Wheel and Axles – consist of two circular objects: a central shaft (axel), inserted through middle of a wheel. – Ex: door knobs, steering wheels, screwdrivers, gears, bicycle wheels

Complex (compound) Machines – consist of two or more simple machines. – Ex: scissors (two levers & two inclined planes: wedges); fishing pole (lever, wheel and axle, pulley); bicycle (levers: handlebars & handbrakes; wheel and axles: gears, wheels, and pedals; screws)