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Name:Simple Machines Study GuideForce and Work-1.) To be considered work, you have to have a force and a distance throughwhich the force acts.2.) What is the formula for work? work force x distance What is the unit for work? joules3.) What does something have to do to be considered a machine?A machine is any device that makes doing work easier.4.) Decide if work is done for each of the following: (Are the requirements for WORK met?)a. Someone is sitting on a cushion on the floor.Work orNO workb. A baseball is hit into the bleachers.WorkorNO workc. Ms. Jarrett holds a doorstop in one place to show you an example of a wedge.WorkorNO workd. A little girl is pushed on a swing.WorkorNO workSimple Machines Basics1.) What are the 2 basic types of simple of machines, of which all other simple machines arevariations of? Also list the other simple machines in the correct category under the heading.inclined planes & leversWedgepulleyScrewwheel and axle2.) In general, what do most simple machines do?Simple machines make work easier by reducing the force needed.3.) Do simple machines make less work? Explain.No. Simple machines make work easier, they do not decrease the amount ofwork. Simple machines can actually make more work due to friction.4.) What do we mean when we say “machines make work easier?” (force vs. distance)Simple machines make work easier to do by decreasing the force required by increasingthe distance over which the work is done.5.) A force applied by a machine to an object is the?a.) resistance forceb.) effort forcec.) force field6.) A force applied to a machine by a person is the?a.) resistance forceb.) effort forcec.) force fieldd.) Jedi forced.) Jedi force7.) Simple machines make work easier, however there are 2 exceptions to this rule. What arethe exceptions, and in each case, what is the “advantage” each machine gives us?1. single fixed pulley – changes the direction of a force2. 3rd class lever – gives us increased speed

Inclined Plane1.) An inclined plane decreases the force needed to lift an object byincreasing the distance that force is applied.2.) In general, less force more distance, and more force less distance3.) If the force required to lift a barrel into the back of a truck was 124 Newtons without a simplemachine, what would the force required to get the barrel into the back of the truck using aramp? (Think in general, you don’t have enough info to calculate.)a.) less than 124 Newtonsb.) more than 124 Newtonsc.) 124 Newtons4.) Inclined planes can increase the amount of work done due to friction .5.) If it takes 45343 joules of work to lift a barrel into the back of a truck without using a simplemachine, how much work would be required to get the barrel into the back of the truck using aramp? (Think in general again, and CONSIDER FRICTION)a.) less than 45343 Joulesb.) more than 45343 Joulesc.) 45343 JoulesIf we consider friction, we can conclude that the work would be slightly more due to the friction.Lever1.) A lever turns on a fixed point, called the fulcrum .2.) Other than multiplying a force, what else can levers do?Change the direction of a force3.) Explain how you would determine what class a lever is. (Look where and be what?)Look in the middle and be FRE --- fulcrum in middle class one, resistance in middle 2,effort in the middle class 34.) What happens to the force needed to move an object as youincrease the length of effort arm?force needed would DECREASE as you increase the effort arm5.) What would happen to the force required if you decreased the length of the effort arm?If you decreased the effort arm, the force needed would increase6.) True or False and explain- ALL LEVERS make work easier.FALSE. The third class lever doesNOT make work easier. They giveyou increased speed.7.) Label the effort, resistance and fulcrumin the pictures below an identify what classof lever it is.

Pulley1.) Pulleys can multiply a force or change is direction .2.) What are the three types of pulleys?Single movable, single fixed, block and tackle3.) How do you find the mechanical advantage of a block and tackle?Count the sections of rope supporting the weight4.) True or False and explain-ALL PULLEYS make work easier.FALSE. Fixed pulleys do not make work easier, they only change thedirection of the force.5.) How does the distance of the string you pull compare to the distance the weight is liftedwhen using a block and tackle system?The distance of the string you pull is much greater than the distance theobject is lifted. (Trading increased distance for decreased force.)6.) What is the MA of a single fixed pulley? 1 single movable pulley? 27.) Find the effort force required to lift the 300 N weight inthe diagram.1- 300 N2- 100 NSimple vs. Compound Machines(mentioned in “machines” reading)1.) What makes something a compound machine instead of a simple machine?Composed of 2 or more simple machines2.) Label each machine with “S” for simple and “C” for compound.a. scissors Cd. pry bar Sb. ramp Se. bicycle Cc. single fixed pulley Sf. shovel S3.) List 3 of your own examples of compound machines. (Remember: Machines help makeWORK easier.Bull dozer, wheelbarrow, nail clippers, etcMechanical Advantage Basics1.) Mechanical advantage is how much the machine multiplies your force.2.) What does it mean about a machine if it has a mechanical advantage of 1?The machines doesn’t increased your effort/ input force. The force the machine applies toan object is the same as the force you put in. It doesn’t “help” you by making youstronger.3.) Would Machines with higher mechanical advantage would take more or less effort force tomake something move?A.) moreb.) Lessc.) the same

4.) Would machines with higher mechanical advantage would take more or less work to makesomething move?A.) more (with friction) b.) Lessc.) the same5.) If you have a choice between a machine with a MA of 4 and a machine with an MA of 6, whichmachine would it make more sense to use?MA of 6 – you would not have to use as much effort forceWheel and Axle1.) Object with larger radius wheel , object with smaller radius axle2.) What would be easier (take less force) to turn and why:An axle with a diameter of 10cm using a 100cm wheelAn axle with a diameter of 10cm using a 50cm wheelWhy?- It has a larger effort wheel (large wheel). When you increase the effort distance, youdecrease the effort force needed.3.) What would require the least amount of work to turn and why:An axle with a diameter of 10cm using a 100cm wheelAn axle with a diameter of 10cm using a 50cm wheelWhy?-Both amounts of work are the same due to the axles being the same. The 100cmwheel would just be easier because it travels a greater distance.4.) Calculate the IMA for the following machines. Show your work.Rw 11 cmRa 3 cmIMA 3.7Ra 0.5 mRw 3 mIMA 6dw 2.4 mda 0.8 mIMA 3The Screw1.) Which of the screws to the right (A or B) would require thegreatest amount of force to drive into a piece of wood? Why?A – There are less threads so there is less distance. There is moreforce required for a screw with less distance.2.) Which of the screws to the right (A or B) would be the easiest todrive into a piece of wood? Why?B – There are more threads so there is more distance. Since therule is the greater the distance, the less the force, there is LESSforce required for the screw with more threads.3.) Which of the above screws (A or B) would have the greatest mechanical advantage?B – more threads, more distance, less force4.) What is a specific advantage we discussed of using a screw instead of an inclined plane?(Think staircases) completing the same goal using a smaller space

The Wedge1.) What does the wedge do as it moves into a material?Separates the material2.) Of the two wedges to the right, which do you think would require theleast amount of force if you wanted to separate those objects 8cm andwhy?B- it has a greater distance (length) and the rule is when you increase thedistance, you decrease the force (make work easier)4.) What is a major difference between the wedge and an inclined plane?The wedge moves3.) Measure and calculate the IMA of the wedges.Height 1.8 cmHeight 2.6 cmSlope 3 cmSlope 2.4 cmIMA 3 cm/1.8 cm 1.7IMA 2.4cm/2.6 cm .92Calculations: Show your work!Work force x distanceYou will be given the following on your test:FRLength of slopeIMA wedge -------------------------Height or thicknessDEMA x FEMA Resistance ForceEffort ForceRadius wheelIMA x DRI.M.A Effort DistanceResistance DistanceIMA wheel and axle ------------------------Radius axle1.) A clown is trying to lift a refrigerator full of wigs a heightof 2M. It would take him a force of 60 Newtons to lift thefridge without a simple machine.a.) Exactly How much work would be required to lift thisfridge of wigs without a machine?Force 60 NDistance 2 MWork Force x DistanceW 60 Newtons x 2 MWork 120 Joulesb.) Assuming no friction, how much work would be required to lift the fridge of wigs with alever that has a mechanical advantage of 6?120 joules – the amount of work would not change by using the machine, the work wouldjust be easierc.) Assuming no friction, how much effort force would be required to lift the fridge of wigs with alever that has a mechanical advantage of 6?60 N / 6 Force 10 N

2.) What is the force needed to lift a magic school bus if you use a lever with a mechanicaladvantage 25. The force required to lift the magic school bus without a lever would be 1000 N.M.A Resistanceeffortoreffort resistanceM.AResistance 1000 NEffort ?M.A 2525 1000NEffortorEffort 1000N25M.A 403.) How much work is being done by a penguin pushing a purple piano with a force of 50 N up aramp that is 8 meters long?Force 50 NWork Force x DistanceW 50 Newtons x 8 MWork 400 JoulesDistance 8 M4.) What is the mechanical advantage if a unicorn uses its horn as a lever to open a door 2 feetwide using 300 N of force, which would normally take about 900N to open without a simplemachine?M.A ResistanceeffortResistance 900 NEffort 300 NM.A ?M.A 900 N300 NM.A 35.)How much work is required to lift a bag of cat litter 2 meters, if the bag has a force of 40N?Force 40Distance 2 MWork Force x DistanceW 40 Newtons x 2 MWork 80 Joules6.) Melvin the mighty monkey is trying to get a big bag of bananas into his tree house. It takes90 Newtons of force to lift into a tree without using a simple machine. He then makes the workeasier by putting a ramp that is 10 feet long up to his tree house, which allows him to move thebag of bananas with 10 Newtons of force. What is the Mechanical Advantage of this inclinedplane?Resistance 90 NEffort 10 NM.A ?M.A ResistanceeffortM.A 90 N10 NM.A 97.) What is the Ideal Mechanical Advantage of a lever whose effort arm measures 55cm andwhose resistance arm measures 5 cm?Resistance 5 cmI.M.A Effort ArmI.M.A 55 cmI.M.A 11Effort 55 cmResistance Arm5 cmI.M.A Lever ?8.) What is the Ideal Mechanical Advantage of an inclined plane that has a length of 400cm and aheight of 50cm?Resistance 50 cmEffort 400c mI.M.A Lever ?I.M.A Effort dist(Length)Resistance dist(Height)I.M.A 400 cm50 cmI.M.A 89.) What is the ideal mechanical advantage for a lever whose fulcrum is at 20cm?Resistance 20cm I.M.A Effort ArmI.M.A 80cmEffort 80cmResistance Arm20 cmI.M.A Lever ?I.M.A 4

d. A little girl is pushed on a swing. Work or NO work Simple Machines Basics 1.) What are the 2 basic types of simple of machines, of which all other simple machines are variations of? Also list the other simple machines in the correct category under the heading. _inclined planes_ & _levers_ Wedge pulley