LEVERSInvestigation 1:

Set the challenge…

Can you lift a heavy load with only one finger?

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

Do you know that you can perform stunning feats of brute strength, far more amazing than the most

powerful athletes? It’s true, you can roll big boulders around

like basketballs, lift half a dozen sixth graders off the floor with one hand, pull nails right out of wood, and flip the cap off a bottle of root beer with no difficulty at all.

What’s the secret?

LEVERAGE These tasks can be accomplished by using

the aid of a lever!

A lever is a simple machines that provides you with an advantage

It can make work easier…

1. make a load easier to lift

2. reduce effort

3. Increase speed or distance

Parts of a Lever

There are 4 parts of a lever system:

Fulcrum Effort Load Lever Arm

REMEMBER:

FELLA

How does it work?

How does it work? The lever arm is the straight, rigid bar The pivot point is the fulcrum A load is on one side on the lever Effort is applied to the other side to life the

load Effort applied to one side of the lever lifts

the load on the other side.

Let’s look at some common examples…

Can you label the parts?

Levers?

Levers

Can you find my FELLA?

Draw & Label my parts on the note card provided

~Vocabulary~Please record the following in your packet.

Lever = a simple, rigid device that contains a fulcrum

1. Fulcrum = the pivot point or fixed point that the lever arm can rotate around

2. Effort = the force applied to move the load

3. Load = a mass lifted by the lever

4. Lever arm = the rigid bar or beam

How much force is needed to push or pull a load? It is measured in newtons

Newtons = The newton, usually abbreviated as N, is the Standard International unit of force.

Force is measured in newtons

Take a moment to learn about using spring scales!

Apply what you have learned…

A mass of 1 kg pulls or pushes down (because of gravity) with a force of 10 N

If a 5 kg cat is asleep on one end of a lever arm, you will have to push down on the other end of the lever arm with an effort equal to the force of _________ or the cat won’t budge.

Answer

If

1 kg needs a force of 10 N

Then,

5 kg needs a force of 50 N

To keep in mind while measuring… When you attach the scale to the lever with

the rubber band, the mass of the scale itself, being pulled by gravity, exerts a force.

However, you will see that the effort is 0 N In fact, the weight of the scale is pulling

down with a force of 0.5 N Add on .5 N to the scale reading whenever

you are pulling down with the scale!