Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 1- part 1Investigation 1- part 1

Levers: Introduction to LeversLevers: Introduction to Levers

How can a lever make work How can a lever make work easier?easier?

ENGAGEENGAGE

How could you lift your How could you lift your teacher in the air? teacher in the air?

Could you do it with one Could you do it with one hand?hand?

EXPLOREEXPLORE

Can you lift the load using only Can you lift the load using only one finger?one finger?

Does it always take the same Does it always take the same amount of force to lift the load?amount of force to lift the load?

Where should you press to lift Where should you press to lift the load with the least force?the load with the least force?

Word BankWord BankLeverLeverLever ArmLever ArmFulcrumFulcrumLoadLoadEffortEffortNewtonNewton

Content/InquiryContent/InquiryA lever can make a load easier A lever can make a load easier

to lift, it can move loads, and it to lift, it can move loads, and it reduces the effort.reduces the effort.

In a lever system the In a lever system the fartherfarther from the from the fulcrumfulcrum the effort is the effort is applied, the applied, the greatergreater the the advantageadvantage to the lever user. to the lever user.

Student questions?Student questions?

““Simple Machines”Simple Machines”

Identify 5 or more simple machines that Identify 5 or more simple machines that we use every day. we use every day.

For each simple machine listed above, tell For each simple machine listed above, tell why people use the tool?why people use the tool?

Archimedes, the Greek mathematician and Archimedes, the Greek mathematician and scientist’s idea of moving the earth, is scientist’s idea of moving the earth, is similar to how you could lift your teacher. similar to how you could lift your teacher. Explain.Explain.

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 1- part 2Investigation 1- part 2

Levers: Lever Experiment ALevers: Lever Experiment A

What happens to the effort What happens to the effort needed to lift a load as the needed to lift a load as the position where the effort is position where the effort is applied changes?applied changes?

Class DataClass Data

Position ofPosition of Effort (scale + 0.5 N) Effort (scale + 0.5 N) Effort (cm)Effort (cm) 2.5 cm2.5 cm 9.4 N9.4 N 9.9 N9.9 N 5.0 cm5.0 cm 4.5 N4.5 N 5.0 N5.0 N 10.0 cm10.0 cm 15.0 cm15.0 cm 20.0 cm20.0 cm 25.0 cm25.0 cm

Word BankWord Bank

Two-coordinate graphTwo-coordinate graphAdvantageAdvantage

Content/InquiryContent/Inquiry

The The fartherfarther the effort is from the effort is from the fulcrum, the the fulcrum, the easiereasier it is to it is to lift the load.lift the load.

Student questions?Student questions?

““Class-1 Levers”Class-1 Levers”

What is a mechanical advantage?What is a mechanical advantage? What advantage rule can we state about a class-What advantage rule can we state about a class-

1 lever?1 lever? What is the cost of making the work easier?What is the cost of making the work easier? Get a tool from the teacher and draw a diagram Get a tool from the teacher and draw a diagram

of it. Identify and label on your drawing the of it. Identify and label on your drawing the location of the load, effort, and fulcrum. Notice location of the load, effort, and fulcrum. Notice the distance of the load to the fulcrum.the distance of the load to the fulcrum.

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 1- part 3Investigation 1- part 3

Levers: Lever Experiment BLevers: Lever Experiment B

What happens to the effort What happens to the effort needed to lift a load as the needed to lift a load as the position of the load changes?position of the load changes?

Content/InquiryContent/Inquiry

The effort needed to lift the The effort needed to lift the load load decreasesdecreases as the load as the load gets gets closercloser to the fulcrum; the to the fulcrum; the effort effort increasesincreases as the load as the load gets gets fartherfarther from the fulcrum. from the fulcrum.

Student questions?Student questions?

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 2- part 1Investigation 2- part 1

More More Leverage: Lever ClassesLeverage: Lever Classes

How many ways can you How many ways can you arrange the fulcrum, load, and arrange the fulcrum, load, and effort in a lever system?effort in a lever system?

Word BankWord Bank

Class-1 leverClass-1 leverClass-2 leverClass-2 leverClass-3 leverClass-3 lever

Content/InquiryContent/Inquiry

Levers can be set up in three Levers can be set up in three basic ways. They are called basic ways. They are called class 1, class 2, and class 3.class 1, class 2, and class 3.

Student questions?Student questions?

““The Wheel and Axle”The Wheel and Axle”When you use a wrench to tighten a bolt, When you use a wrench to tighten a bolt,

are you looking for a gain in effort or are you looking for a gain in effort or distance?distance?

When you use a windlass to raise a bucket When you use a windlass to raise a bucket from a well, what is the gain?from a well, what is the gain?

How do you think the key to a music box How do you think the key to a music box works, in terms of a wheel and axle?works, in terms of a wheel and axle?

How do you think the front wheel and the How do you think the front wheel and the rear wheel of a bicycle are different? Which rear wheel of a bicycle are different? Which one is the wheel and axle? Explain how a one is the wheel and axle? Explain how a bicycle works.bicycle works.

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 2- part 2Investigation 2- part 2

More More Leverage: Lever DiagramsLeverage: Lever Diagrams

What conventions can be What conventions can be used so we can communicate used so we can communicate in the same language and in the same language and have an efficient way to record have an efficient way to record the lever systems we build?the lever systems we build?

Word BankWord Bank

DiagramDiagram

Content/InquiryContent/Inquiry

A diagram uses a system of A diagram uses a system of symbols and conventions to symbols and conventions to communicate information communicate information about lever designs.about lever designs.

Student questions?Student questions?

“ “ Class-2 Levers”Class-2 Levers”What is the mechanical advantage of the What is the mechanical advantage of the

class-2 lever?class-2 lever?What advantage rule can we state about a What advantage rule can we state about a

class-2 lever?class-2 lever?What is the load in a bellows?What is the load in a bellows?How is the bellows like a nutcracker and How is the bellows like a nutcracker and

garlic press?garlic press?

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 2- part 3Investigation 2- part 3

More More Leverage: Real-World LeversLeverage: Real-World Levers

What classes of levers can we What classes of levers can we find in the real world?find in the real world?

Content/InquiryContent/InquiryMany common tools use Many common tools use

levers: scissors, pliers, bottle levers: scissors, pliers, bottle openers, hammers, openers, hammers, wheelbarrows, and brooms, to wheelbarrows, and brooms, to name a few.name a few.

Effort is reduced as the load Effort is reduced as the load moves closer to the fulcrum.moves closer to the fulcrum.

Student questions?Student questions?

““Class-3 Levers”Class-3 Levers”What is the mechanical advantage of a What is the mechanical advantage of a

class-3 lever?class-3 lever?What advantage rule can we state about a What advantage rule can we state about a

class-3 lever?class-3 lever?Explain why the catapult is a class-2 lever Explain why the catapult is a class-2 lever

when it is being loaded and a class-3 lever when it is being loaded and a class-3 lever when it is hurling a rock.when it is hurling a rock.

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 2- part 4Investigation 2- part 4

More More Leverage: Lever PicturesLeverage: Lever Pictures

What other levers do we find What other levers do we find around us?around us?

““The Inclined Plane”The Inclined Plane” What is the advantage of an inclined plane?What is the advantage of an inclined plane? What is the disadvantage?What is the disadvantage? What simple machine is used to make a What simple machine is used to make a

wheelchair ramp?wheelchair ramp? How can a plank be used as an inclined plane?How can a plank be used as an inclined plane? Are there inclined planes in our school?Are there inclined planes in our school? Which trail would be the easiest to hike to get to Which trail would be the easiest to hike to get to

the top of the hill?the top of the hill? What is the disadvantage if you take the easiest What is the disadvantage if you take the easiest

route?route?

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 3- part 1Investigation 3- part 1Pulleys: 1-Pulley SystemsPulleys: 1-Pulley Systems

How much effort is needed to lift How much effort is needed to lift a load in a one-pulley system? a load in a one-pulley system?

Is it always the same?Is it always the same?

Word BankWord Bank

PulleyPulleyFixed pulleyFixed pulleyMovable pulleyMovable pulleyMechanical advantageMechanical advantageDirectional advantageDirectional advantage

Content/InquiryContent/InquiryA single pulley can be set up A single pulley can be set up

as a fixed pulley or a movable as a fixed pulley or a movable pulley to lift a load.pulley to lift a load.

Single fixed pulleys change Single fixed pulleys change the direction of effort. Single the direction of effort. Single movable pulleys reduce the movable pulleys reduce the effort needed to lift the load.effort needed to lift the load.

Student questions?Student questions?

““Pulleys”Pulleys”

What is a compound pulley?What is a compound pulley?What is a block and tackle?What is a block and tackle?

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 3- part 2Investigation 3- part 2Pulleys: 2-Pulley SystemsPulleys: 2-Pulley Systems

How many ways can two How many ways can two pulleys be assembled?pulleys be assembled?

Can two pulleys give more Can two pulleys give more advantage than one pulley?advantage than one pulley?

Word BankWord Bank

Simple machineSimple machine

Content/InquiryContent/InquiryTwo pulleys can provide Two pulleys can provide

greater mechanical advantage greater mechanical advantage than one when lifting loads.than one when lifting loads.

Simple machines provide Simple machines provide mechanical or other mechanical or other advantage.advantage.

Student questions?Student questions?

““Dear Boss”Dear Boss”

Does the poem explain how Does the poem explain how pulleys really work?pulleys really work?

What kind of pulley system did What kind of pulley system did the bricklayer use?the bricklayer use?

Relate to poem-do you know?Relate to poem-do you know?What country? Bloody? Sod? Hod?What country? Bloody? Sod? Hod?Why is this poem humorous????Why is this poem humorous????

Essential Question: Levers & Pulleys Essential Question: Levers & Pulleys Investigation 3- part 3Investigation 3- part 3

Pulleys: Pulley GamePulleys: Pulley Game

How many pulley systems can How many pulley systems can you set up?you set up?

““The Wedge”The Wedge”How do they keep the airplane from How do they keep the airplane from

moving?moving?How is a wedge related to an inclined How is a wedge related to an inclined

plane?plane?What are some of the wedges you have What are some of the wedges you have

seen in use?seen in use?How does the slope of a wedge’s planes How does the slope of a wedge’s planes

affect the sharpness of a blade?affect the sharpness of a blade?

Explain how these items use the wedge!Explain how these items use the wedge!

NailNail PinPin NeedleNeedle ChiselChisel Ax bladeAx blade Saw bladeSaw blade Knife bladeKnife blade Scissors bladeScissors blade Bow of a shipBow of a ship Nose of an airplaneNose of an airplane Woodpecker’s billWoodpecker’s bill

Essential Question: Levers & Pulleys Investigation Essential Question: Levers & Pulleys Investigation 4- part 14- part 1

Pulleys at Works: The Effort in Pulley SystemsPulleys at Works: The Effort in Pulley Systems

How can we predict the effort How can we predict the effort needed to lift the load in a needed to lift the load in a pulley system?pulley system?

Content/InquiryContent/InquiryThe greater the number of ropes The greater the number of ropes

supporting the load, the less the supporting the load, the less the effort needed to lift the load.effort needed to lift the load.

The effort needed to lift a load can The effort needed to lift a load can be predicted from the weight of be predicted from the weight of the load and the number of ropes the load and the number of ropes supporting the load.supporting the load.

Student questions?Student questions?

““The Work of Pulleys”The Work of Pulleys”Where do you find pulleys in the real Where do you find pulleys in the real

world?world?How does a chain hoist work?How does a chain hoist work?What modern-day machine has replaced What modern-day machine has replaced

pulleys?pulleys?

Essential Question: Levers & Pulleys Investigation Essential Question: Levers & Pulleys Investigation 4- part 24- part 2

Pulleys at Works: Measuring DistancePulleys at Works: Measuring Distance

What is the relationship What is the relationship between the mechanical between the mechanical advantage and the distance advantage and the distance the load and the effort move in the load and the effort move in a pulley system?a pulley system?

Content/InquiryContent/InquiryThe benefits gained by using The benefits gained by using

simple machines are always simple machines are always balanced by cost. When the balanced by cost. When the benefits outweigh the costs, the benefits outweigh the costs, the machine is a useful tool.machine is a useful tool.

In a lever system, a reduction in In a lever system, a reduction in effort is balanced by the distance effort is balanced by the distance over which the effort must act.over which the effort must act.

Student questions?Student questions?

““The Screw”The Screw”How is a screw a variation of an inclined How is a screw a variation of an inclined

plane?plane?What tool is used to turn the screw into the What tool is used to turn the screw into the

wood?wood?What kind of simple machine is the What kind of simple machine is the

screwdriver?screwdriver?

Essential Question: Levers & Pulleys Investigation Essential Question: Levers & Pulleys Investigation 4- part 34- part 3

Pulleys at Works: Choosing your own InvestigationPulleys at Works: Choosing your own Investigation

What other lever and pulley What other lever and pulley systems can you design?systems can you design?

““Thank you, Mr. Clumpet”Thank you, Mr. Clumpet”Are there any levers? What types of levers Are there any levers? What types of levers

are they?are they?Are there any pulleys? What types of Are there any pulleys? What types of

pulleys are they?pulleys are they?Are there any wheel and axles?Are there any wheel and axles?Are there any inclined planes? What types Are there any inclined planes? What types

or variations of inclined planes are they?or variations of inclined planes are they?