Soc: 20 Lever Systems Flashcards
What is a lever?
A system of bones and muscles working together to bring about movement.
How many components does a lever have?
4
What does a fulcrum mean?
A pivot or point around which the lever rotates.
What does a load mean in a lever system?
The force that is applied by the lever system. The load is the object that you want to move,e.g, a dumbbell with your arm.
What is effort in a lever system?
A force that is applied by the user of the lever system. The effort is supplied by your muscles.
What is the lever arm in a lever system?
A rigid bar such as a bone.
How many different classes of levers are there?( name them)
3 First class Second class Third class
Where are the parts of the lever system in a first class lever?
Fulcrum-middle
Load- left side
Effort- right side
Where are the parts of the lever system in a second class lever?
Load- in the centre
Fulcrum- right side
Effort- left side
Where are the parts of the lever system in a third class lever?
Effort- in the centre
Fulcrum- left side
Load- right side
Give an example of a first class system and what is what?
Trciep dip:
Fulcrum- The elbow
Load- Weight held in hand
Effort- Applied by the tricep
Give an example of a second class system and what is what?
Calf raise (standing on tippy toes):
Load-Body weight
Fulcrum- Ball of the feet
Effort- Force applied by gastrocnemius muscles (by pulling the heel).
Give an example of a second class system and what is what?
Bicep curl:
Fulcrum- Elbow joint
Load- Dumbbell in your hands
Effort- bicep muscle
What is a mechanical advantage?
When the output of the lever is greater than the input (load is greater than effort)- getting more out than you put in.
What types of levers are an example of a mechanical advantage?
First and second class levers