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Investigation 1:. Levers. 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?.
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Investigation 1: Levers
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? • 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.
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!