Lever Systems

Question 1

What are levers?

Answer 1

Levers are simple machines.

Capable of altering direction and magnitude of a force.

They are able to: Balance 2 or more forces, provide a force advantage, provide an advantage in speed.

Question 2

What is the fulcrum?

Answer 2

The Joint (Axis of rotation).

Question 3

What is the effort?

Answer 3

Point of application of the force.

Question 4

What is the load?

Answer 4

The mass or object that is being moved.

Question 5

What are examples of Class 1 levers?

Answer 5

See-saws, Scissors, Crowbars.

In the human body, an example is the neck as it shifts from flexion to extension.

Class 1 lever is the most versatile of all levers. It can afford a speed and/or force advantage

Question 6

What are examples of Class 2 levers?

Answer 6

Wheelbarrows, Doors.

In the human body, an example is the ankle joint (Fulcrum) and the gastrocnemius is the effort.

A Class 2 lever affords a force advantage: a relatively small effort can lift a large load

Question 7

What are examples of a class 3 lever?

Answer 7

Brooms, Baseball bats.

An example in the human body is during a bicep curl.

The biceps muscle (effort) inserts on the radius (at the end of which is the load itself) in combination with the elbow joint (fulcrum).

THIS IS THE MOST COMMON LEVER IN THE HUMAN BODY.