SIMPLE MACHINES STUDY GUIDE. Answer key. * You need to know the
definitions of the following words: force: a push or a pull that changes the way an
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SIMPLE MACHINES STUDY GUIDE Answer key * You need to know the definitions of the following words: force: a push or a pull that changes the way an object moves gravity: an invisible force that pulls objects towards earth friction: a force caused by two objects rubbing together, it slows moving objects work: when a force moves an object through a distance fulcrum: the point at which a lever turns or pivots
* You need to know what the following do and/or look like (an example of each simple machine would be helpful): wedge : two inclined planes placed back to back, used to push objects apart (axe, knife, push pin) wheel and axle: a wheel attached to a rod (bicycle, cars, roller skates) screw: an inclined plane wrapped around a rod, used to hold objects together (light bulb, screw) pulley: made up of a wheel and rope or chain (crane, wishing well) lever: made up of a bar supported underneath at some point, it turns or pivots around a fulcrum (seesaw) inclined plane: a slanted surface (ramp, slanted road, slide)
* Be able to describe and draw a simple machine that can be found on the playground. You will need to label it on your test, and give a couple of sentences on how you use it. ~ Slide (inclined plane if it is straight, screw if it is a spiral) climb up an inclined plane and slide down another inclined plane (screw) quickly ~Seesaw (lever) one person applies a pushing force and then the other person pushes with a force ~ Stairs (inclined plane) to get up to the top of the equipment * All of the following materials COULD be used to conduct an experiment with a simple machine: pulling a sand bag up a ramp; moving the fulcrum of a lever; changing the amount of weight lifted by a pulley. * What is a simple machine? A machine (object, tool) that makes work easier.
* Be able to explain one way a pulley can be used by a third grader. to lift a box to your tree house, to raise a flag on a flagpole, to lift water out of well
* Be able to explain what a compound machine is and provide an example. A machine made up of 2 or more simple machines Examples: stapler (wedge, lever, screw), wheelbarrow (wheel and axle, screw, inclined plane, lever) bicycle (wheel and axle, screw, lever, pulley)
* Match the word on the left with the letter of the definition on the right. (This will help you with the definitions on the other side.) 1. __B__ force
a. when a force moves an object through a distance
2. __D__ gravity
b. a push or pull that changes the way an object moves
3. __C__ fulcrum
c. the support that a lever turns or pivots around
4. __E__ friction
d. an invisible force that pulls objects towards each other
5. __A__ work
e. a force caused by two object rubbing together, the force slows moving objects
Match the word on the left with the letter of the definition on the right. (This will help you with the definitions on the other side.)
1. _B_ gears
a. a simple machine used to hold objects together is a
2. _G_ wheel and axle
b. wheels with jagged edges like teeth are
3. _F_ wedge 4. _A_ screw
c. a machine made of a bar that is supported underneath at some point is a d. a slanted road and ramp are two examples of
5. _C_ lever
e. a simple machine made of a rope and a wheel is
6. _D_ inclined plane f. a simple machine that is used to push objects apart is a 7. _E_ pulley
g. cars and roller skates both have a simple machine of a rod attached to a wheel that is a
