Soc20- Levers

Question 1

What is a lever?

Answer 1

In your body, the term “lever” refers to a system of muscles and bones together to bring about movement

When you exercise, your muscles pull on your bones, and your bones create movement, acting as levers

Question 2

How does a lever work and what are the 4 components of the structure of a lever?

Answer 2

1) Fulcrum - (or pivot) - the point around which the lever rotates (joints)
2) Load - the force that it applied by the lever system (resistance / object)
3) Effect - a force that is applied by the user of the lever system (muscles)
4) Lever arm - a rigid bar such as a bone

Question 3

What are the different types of levers?

Answer 3

1) First class
2) Second class
3) Third class

Question 4

Which type of lever is First class?

Answer 4

Fulcrum in the middle

Question 5

Which type of lever is Second class?

Answer 5

Load in the middle

Question 6

What type of lever is Third class?

Answer 6

Effort in the middle

Question 7

Name two examples of First Class Levers?

Answer 7

Example 1: Tricep Dip

The elbow is the fulcum which sits between the load (bodyweight) and the effort applied by the tricep.

Example 2: Nodding your head

The neck joint (atlas and axis) is the fulcrum which sits between the load (head) and the effort applied by the neck muscle (sternocleidomastoid).

Question 8

Name two examples of Second Class Levers?

Answer 8

Example 1: Calf raiser

The body weight (load) sits between the toes and the ball of the feet (fulcrum) and the gastrocnemius muscles apply the effort by pulling the heel.

Example 2: Lifting a wheelbarrow

The weight on the wheelbarrow you’re carrying is the load, which sits between the wheel (fulcum) and the handle (effort).

Question 9

Name two examples of Third Class Levers?

Answer 9

Example 1: Bicep curl

The effort is applied by the bicep which is between the fulcum at the elbow joint and the weight in your hands (load).

Example 2: Using a spade

The effort is applied by the foot (gastrocnemius), which is between the fulcrum at the handle and the weight of the soil (load).

Question 10

What is the definition of Mechanical Advantage?

Answer 10

A large load can be lifted with a relatively small amount of effort

Question 11

What is the definition of Mechanical Disadvantage?

Answer 11

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.