Welcome to a world full of Welcome to a world full of machines!machines!

Copy the following terms in your lab Copy the following terms in your lab book: book: (you might want to leave a space because you need to (you might want to leave a space because you need to have a definition for each at the end of the unit)have a definition for each at the end of the unit)

Wheel and axleWheel and axle ScrewScrew MachineMachine

Inclined PlaneInclined Plane WedgeWedge EfficiencyEfficiency

PulleyPulley FulcrumFulcrum WorkWork

LeverLever Compound MachineCompound Machine EnergyEnergy

Simple MachineSimple Machine

The 6 Simple MachinesThe 6 Simple Machines

All machines are made up of some All machines are made up of some of the 6 simple machines. of the 6 simple machines. • Wheel and axleWheel and axle• PulleyPulley• LeverLever• WedgeWedge• ScrewScrew• Inclined PlaneInclined Plane

Why do we need simple Why do we need simple machines?machines?

Work means that we are exerting Work means that we are exerting force and moving somethingforce and moving something. The . The 6 simple machines make our work 6 simple machines make our work easier. easier. We won’t have to use as We won’t have to use as much forcemuch force with our simple with our simple machines.machines.

The Wheel and AxleThe Wheel and Axle

Two or more wheels Two or more wheels are connected by an are connected by an axle. axle.

The wheel turns with The wheel turns with or around the axle.or around the axle.

This car wheel has a This car wheel has a big axle that it big axle that it rotates around when rotates around when the car moves. the car moves.

Why do we need wheels?Why do we need wheels?

Wheels help us move heavy objects. Wheels help us move heavy objects. They roll easily.They roll easily. Did you know a doorknob is really Did you know a doorknob is really

two wheels connected by an axle? two wheels connected by an axle? You can’t see the axle because it’s You can’t see the axle because it’s inside the wheels, but it’s there! inside the wheels, but it’s there!

If there wasn’t an axle, the doorknob If there wasn’t an axle, the doorknob wouldn’t turn!wouldn’t turn!

Another kind of wheel is Another kind of wheel is called a gear!called a gear!

A gear is a wheel with teeth. A gear is a wheel with teeth. The teeth fit in between each other The teeth fit in between each other

and turn. and turn. When one gear turns, its teeth push When one gear turns, its teeth push

against the teeth of the other gear against the teeth of the other gear and they both turn. and they both turn.

There are gears on your bike, on a There are gears on your bike, on a can opener and on an egg beater.can opener and on an egg beater.

Pulleys Pulleys

Lifting a bucket full of water Lifting a bucket full of water is a lot of work!is a lot of work!

A pulley is a wheel with a A pulley is a wheel with a rope running over it. The rope running over it. The wheel has a groove, called a wheel has a groove, called a sheave, and it keeps the sheave, and it keeps the rope from slipping off the rope from slipping off the wheel. wheel.

Remember, since there is a Remember, since there is a wheel in a pulley there also wheel in a pulley there also has to be an axle!has to be an axle!

These two men are using a These two men are using a pulley to help them lift their pulley to help them lift their

heavy bucket.heavy bucket.

LeversLevers

There are three There are three parts to a lever:parts to a lever:• Load Load • ForceForce• Fulcrum: support Fulcrum: support

or balanceor balance

A seesaw is a leverA seesaw is a lever

Let’s pretend you are Let’s pretend you are riding a seesaw with riding a seesaw with your friend. your friend.

The center support is The center support is the fulcrum, which does the fulcrum, which does not move. not move.

The load is your friend The load is your friend sitting on one end.sitting on one end.

You exert the force at You exert the force at the other end trying to the other end trying to lift your friend off the lift your friend off the ground. ground.

When you push down on When you push down on your seat, (the force) you your seat, (the force) you can lift your friend (the can lift your friend (the load) while the fulcrum load) while the fulcrum acts as the pivot point, acts as the pivot point, making the seesaw go up making the seesaw go up and down. and down.

It’s easy to lift your It’s easy to lift your friend this way instead of friend this way instead of just picking her or him up just picking her or him up by yourself!by yourself!

Levers-First ClassLevers-First Class

In a first class In a first class lever the fulcrum lever the fulcrum is in the middle is in the middle and the load and and the load and effort is on either effort is on either sideside

Think of a see-Think of a see-sawsaw

Levers-Second ClassLevers-Second Class

In a second class In a second class lever the fulcrum lever the fulcrum is at the end, with is at the end, with the load in the the load in the middlemiddle

Think of a Think of a wheelbarrowwheelbarrow

Levers-Third ClassLevers-Third Class

In a third class In a third class lever the fulcrum lever the fulcrum is again at the is again at the end, but the effort end, but the effort is in the middleis in the middle

Think of a pair of Think of a pair of tweezerstweezers

The Wedge The Wedge

A wedge is used to A wedge is used to split, tighten, or secure split, tighten, or secure a hold. a hold.

A wedge is usually a A wedge is usually a triangle shape with a triangle shape with a sharp point. sharp point.

If you apply force at If you apply force at one end, the wedge one end, the wedge will go between will go between something, in this case something, in this case an ax splits a piece of an ax splits a piece of wood.wood.

Where can we find Where can we find wedges?wedges?

Wedges that split:Wedges that split: Your teeth!Your teeth! Every time you bite Every time you bite

into something, you into something, you are using a wedge.are using a wedge.

Wedges that cut:Wedges that cut: A saw!A saw! A knife!A knife!

Wedges that Wedges that tighten:tighten:

A doorstop to keep A doorstop to keep the door open.the door open.

Wedges that hold Wedges that hold things together:things together:

A nail holds wood A nail holds wood to a wall or other to a wall or other wood.wood.

The ScrewThe Screw There are three parts to a There are three parts to a

screw.screw. The first part is called the head The first part is called the head

and is the part that you exert a and is the part that you exert a force on.force on.

The second part is known as The second part is known as the shaft. It has ridges, called the shaft. It has ridges, called threads that wind around the threads that wind around the screw. The space in between screw. The space in between the ridges or threads is called the ridges or threads is called the pitch. If it doesn’t have the pitch. If it doesn’t have the threads, it is probably just the threads, it is probably just a nail.a nail.

The last part is the tip . It is The last part is the tip . It is the sharp portion of the screw the sharp portion of the screw that allows it to get through that allows it to get through material. material.

How to use a screw:How to use a screw:

Fasten two things togetherFasten two things together When you turn it, the threads cut a When you turn it, the threads cut a

groove in the material, making a groove in the material, making a hole. The groove holds the screw hole. The groove holds the screw tightly in place. tightly in place.

To remove the screw you turn it To remove the screw you turn it the opposite way, you can’t just the opposite way, you can’t just pull it out. pull it out.

The Inclined PlaneThe Inclined Plane

It is a slanted surface It is a slanted surface or ramp. or ramp.

It makes moving It makes moving objects easier. objects easier.

Roads are also Roads are also inclined planes. inclined planes. Instead of going Instead of going straight up, like this: straight up, like this: roads go up at small roads go up at small angles, like the angles, like the picture.picture.

The 6 Simple MachinesThe 6 Simple Machines

Lever Pulley

Wheel and Axle

WedgeScrew

Inclined Plane

Rube Rube GoldbergGoldberg

Rube Goldberg was an Rube Goldberg was an artist, inventor, engineer, artist, inventor, engineer, author and sculptor. He is author and sculptor. He is best known for his comical best known for his comical drawings of crazy drawings of crazy contraptions and inventions.contraptions and inventions.www.rubegoldberg.com

Complex machine Complex machine