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WARM UP: A world full of machines! There are machines all around us! Turn to your neighbor and discuss what kinds of machines you saw on your way to school today. Make a list/draw 5-10 of them - LEFT p. 47.
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Simple Machines Notes Copy Words and Pictures!
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Machines Help us Work b Work is done when something is moved a certain distance (d) against a force (F) b W=Fd preAP Pushing on a wall Lifting Weights
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Machines Help us Work b Work is done when something is moved a certain distance (d) against a force (F) b W=Fd
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Most machines are Compound Machines b More than one simple machine together
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Simple Machine: b Something that makes work easier to do with few or no moving parts. b Pulleys and inclined planes (ramps) are simple machines. Pulley Inclined Plane
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There are 6 Simple Machines SM sort Lever Pulley Wheel and Axle Wedge Screw Inclined Plane
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SM Sort b Each person received a machine when you came into class.
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Real- world Examples
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Why do we need machines? Machines help us do work (make it easier) Machines help us do work (make it easier)-- the same amount of work we would have done anyway! Machines do not do the work for us and they do not decrease the amount of work! Machines do not do the work for us and they do not decrease the amount of work! [Law of Conservation of Energy] Machines change the amount of effort force or the direction of the force to make work easier.
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If you wanted to get to point C on the illustration above, you have two options: start at A and go straight up, or start at B and walk up the slope. Which is easier? Which requires more work? The only thing you have control over is if you put forth a lot of effort over a short distance (situation A-C) or a little effort for a long distance (situation B-C). Load/Resistance Effort
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Inclined Planes b b Also called a ramp b b As an inclined plane gets shorter in height or longer in length, the amount of force necessary to move an object decreases.
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Pulleys b b A pulley system consists of a rope attached to a grooved wheel and a load. b b Pulleys put the weight of the load over different sections of the rope. They reduce the force needed to lift the load by increasing the distance the load is moved. Effort Load
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The Load/Resistance b For all simple machines, an object's mass is related to the amount of force needed to move it.
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BrainPOP b Inclined planes b Pulleys
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Review #1 b b ________________________ are devices that make work easier. Simple machines have _______________________ parts. One example of the________________________ is a ramp, which helps you move something from a lower level to higher level. Another example is the ________________________, which is a grooved wheel with a rope around it.
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Review #2 Inclined _____________________ and ____________________ reduce the amount of force that must be exerted on an object in order to ____________ it. The larger an object’s ________________, the larger the amount of ________________ needed to move it. As an inclined plane ____________________in length, the amount of force necessary to move an object a certain height _____________________.
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Stations 12 – See WS b Kids assignment b Pulleys b Spring scale, mass, etc.
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Project b Your group must build a pulley and inclined plane system that moves a payload from
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