Soc 20: Levers Flashcards
What is a lever?
In your body, the term ‘lever’ refers to a system of muscles and bones working together to bring about movement.
How does a lever work?
A lever is a structure that has four components:
1) Fulcrum - (or pivot) - the point around which the lever
rotates (joints).
2) Load - the force that is applied by the lever system
(resistance/ object).
3) Effort - a force that is applied by the user of the lever
system (muscles).
4) Lever arm - a rigid bar such as a bone.
What is a Fulcrum?
(or pivot) - the point around which the lever
rotates (joints).
What is a load?
the force that is applied by the lever system
(resistance/ object).
What is a Effort?
a force that is applied by the user of the lever
system (muscles).
What is a lever arm?
a rigid bar such as a bone.
What shape is used to represent a Fulcrum?
Triangle
What shape represents a load?
Square
What image represents Effort
Arrow
What image represents a lever arm?
Bar
Diffrent types of Levers
● 1) First class
● 2) Second class
● 3) Third class
How do we know which type of lever it is?
To recall the order of the levers use the term ‘FLE’ - this will help you to remember which part of the lever is in the middle.
First class lever - Fulcrum is in the middle.
Second class lever - Load is in the middle.
Third class lever - Effort is in the middle.
First Class levers
The fulcrum sits in the middle, between the load and the effort.
What class of Lever would a tricep dip be in?
First Class
What class of lever is nodding your head?
First Class
Second class levers
The load sits in the middle, between the fulcrum and the effort.
What class of lever is calf raises?
Second Class
What class of lever is lifting a wheelbarrow?
Second Class
Third class lever
The effort sits in the middle, between the fulcrum and the load.
What class of lever would be a bicep curl?
Third Class
What class of lever would be using a spade?
Third class
Michanical Advanatges
A large load can be lifted with a relatively
small amount of effort.
Mechanical disadvantages
Third class levers cannot lift as heavy a load
with the same amount of effort, due to the position of
the effort and load from the fulcrum.
