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Group Station
1. Correct the brainpop2. Do the inquiry activity3. Work on the HW questions on the back– Use the power point to help you answer these
questions!
Independent Station Directions1. Make flashcards for the following terms. • Lever• Fulcrum• Resistance/Load• Effort• Mechanical Advantage• 1st class lever (definition comes at the beginning of the slide)• 2nd class lever (Definition comes at the beginning of the slide)• 3rd class lever (definition comes at the beginning of the slide)2. Choose any 10 flash card words and use them in a
complete sentence on a blank piece of paper. DO NOT JUST WRITE THE DEFINITION
3. Practice the flash cards with a neighbor or independently.
Wednesday, March 13th, 2013 Your Learning Goal:
Students will be able to identify and classify different levers in the body and explain lever’s advantage.
Standard: 5c: Students know how bones and muscles work together to provide structural framework for movement.6h: Students know how to compare joints in the body with structures used in machines and simple devices
Table of Contents: 6.8 Levers in the bodyHomework:Due: 3/19
6.8 Lever Inquiry6.8 Flash Cards
Agenda:1. Do-Now2. Stations
Table of Contents:# Title date page6.6 Musculoskeletal Quiz 3/12 11-126.7 Joints 3/13 13-16
3/146.8 Levers In the Body 3/17 17-20
What is the musculoskeletal movement like?
• Muscles and bones work together as A Lever system: Notes tomorrow!
What is a lever• A Lever is rigid bar that pivots at a fixed point • A Fulcrum is the fixed point that a liver pivots at• The effort is the force you put on the lever: Can be up or
down• The resistance/load is the object you are picking up with
your lever
Effort
Fulcrum
Resistance
Mechanical A• Mechanical Advantage is how many times the
force is multiplied in a lever.• Mechanical Advantage: you use less force (effort)
to lift the load than without the lever• This happens when the effort is further from the
fulcrum than the load is from the fulcrum• Mechanical disadvantage happens when the load
is further from the fulcrum than the effort is from the fulcrum.
Mechanical Advantage
What is Mechanical Advantage
Effort Distance ÷ Load Distance
The effort distance from the fulcrum must be greater than the load distance for their to be mechanical advantage
Load
Fulcrum is between the effort and load.• Mechanical advantage only if the effort is further away
than the load• If there is no mechanical advantage, this lever system
only serves to change the direction of motion
Effort
Fulcrum
1st class LeverMedium Lever
Musculoskeletal Levers - 1st Class• Advantage: changes the direction of movement:–Moving your head up and down!!
EffortResistance
Musculoskeletal Levers - 1st ClassTriceps:– The effort is closer
than the load. – Mechanical
disadvantage– Increases the
distance the load moves!
shoulder
EffortFulcrum
Resistance
Effort
Fulcrum
Second Class Lever: Best leverThe resistance is between the effort and fulcrum.
• This means the effort is always further from the fulcrum = Always a mechanical advantage
• Use less force to lift a heavy weight
Resistance
Musculoskeletal Levers - 2nd Class• The action of the calf
is a second class lever when jumping or doing toe raises.
• The body weight is in between the effort (calf muscle) and the fulcrum (toes)
fulcrum
Body weight is the resistance.
Effort force is from the calf muscle on the heal.
Resistance
Effort
Fulcrum
Third Class Lever:Hardest Lever
Effort is between the load and fulcrum: The load is always further = mechanical disadvantage
The lever moves the load a greater distance at a greater speed, but requires a greater force
Musculoskeletal Levers - 3rd Class
FM
R
• Bicep Curls• The bicep pulls on the arm
between the load and the fulcrum: Mechanical disadvantage
• The Speed of the ball increases.
• The distance the ball moves increases
fulcrum
Effort
Resistance
Fulcrum