❌Levers

Question 1

What are the three main components of levers?

Answer 1

Pivot - Fulcrum
Weight to be moved - Resistance
Source of energy - Effort/force

Question 2

What is a fulcrum?

Answer 2

The point which the lever rotates

Question 3

What is the resistance?

Answer 3

The weight to be moved by the lever system.

Question 4

What is the effort?

Answer 4

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

Question 5

What’s an example of levers?

Answer 5

The skeleton forms a system of levers that allows us to move.

The bones act as the levers, the joints are the fulcrums, the effort is provided by the muscle and the resistance is the weight of the body part that is being moved (often against the force of gravity).

Question 6

What are the types of levers?

Answer 6

First class
Second class
Third class

Question 7

What are first class levers?

Answer 7

The fulcrum lies between the effort and resistance

Question 8

What are second class levers?

Answer 8

The resistance is between the fulcrum and effort.

Question 9

What are third class levers?

Answer 9

The effort is between the fulcrum and the resistance.

Question 10

What does FLE, 123 mean?

Answer 10

1 - F (first class levers have the fulcrum in the middle)
2 - L (second class levers have the load/resistance in the middle)
3 - E (third class levers have the effort in the middle)

Question 11

What’s an example of a first class lever?

Answer 11

The movement of the head and neck during flexion and extension.
Extension of the elbow

Question 12

What’s an example of a second class lever?

Answer 12

There is only one example: Plantarflexion of the ankle.

Question 13

What is an example of a third class lever?

Answer 13

Every other joints in the body.

Hip, knee and elbow flexion.

Question 14

What is the effort/force arm?

Answer 14

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

Question 15

What is the resistance arm?

Answer 15

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

Question 16

What is mechanical advantage?

Answer 16

Where the force arm is longer than the resistance arm.

Question 17

What is mechanical disadvantage?

Answer 17

Where the resistance arm is longer than the force arm.

Question 18

What does mechanical disadvantage mean?

Answer 18

The lever system cannot move as heavy a load but can do it faster.
It also has a large range of movement.

Question 19

What does mechanical advantage mean?

Answer 19

The lever system can move a large road over a short distance and requires little force.
It has a small range of movement and it is difficult to generate speed and distance.

Question 20

What lever has the longest effort arm?

Answer 20

Class 2 because it has the most to overcome.

Body weight is in the middle.

Question 21

What’s a sporting example of a first class lever?

Answer 21

A line out throw in rugby.

F = elbow joint 
L = ball (in hands) 
E = triceps

Question 22

What’s a sporting example of a second class lever?

Answer 22

Point in ballet/gymnastics - plantarflexion

F = toes 
L = body weight 
E = gastrocnemius

Question 23

What’s a sporting example of a third class lever?

Answer 23

Bicep curl - Flexion at the elbow.

F = elbow joint 
L = weight 
E = biceps

Question 24

What lever have a high mechanical advantage?

Answer 24

Second class - has to lift the whole body weight. Can generate much larger forces.

Question 25

What lever has a mechanical disadvantage?

Answer 25

Third class - always

First class - tends to have