3.2.2.2 Levers

Question 1

Fulcrum (triangle on diagrams)

Answer 1

The point about which the lever rotates

Question 2

Resistance (square on diagrams)

Answer 2

The weight to be moved by the lever system

Question 3

Effort

Answer 3

The force applied by the user (muscle) of the lever system

Question 4

First class lever
example in the body
Example in sport

Answer 4

The fulcrum lies between the effort and resistance
Extension of the elbow
Line out throw in rugby

Question 5

Second class lever
Example in the body
Example in sport

Answer 5

The resistance is between the fulcrum and effort

Plantar flexion of the ankle

Question 6

Third class lever
Example in the body
Example in sport

Answer 6

The effort is between the fulcrum and resistance

Question 7

Mechanical adavantage

Answer 7

Where the force arm is longer than the resistance arm

Question 8

Mechanical disadvantage

Answer 8

Where the resistance arm is longer than the force arm

Question 9

Force arm

Answer 9

The length of the line between where the fulcrum and effort are labelled

Question 10

Resistance arm

Answer 10

The length of the line between where the fulcrum and the resistance are labelled

Question 11

Example of second class lever
Mechanical advantage
Mechanical disadvantage

Answer 11

Plantarflexion of the ankle
Mechanical advantage: can generate much large forces
Mechanical disadvantage: slow, with a limited range of movement