Soc 20

Question 1

Axis

Answer 1

an imaginary straight line around which a body or object rotates.

Question 2

Fulcrum

Answer 2

the point around which the lever rotates.

Question 3

Load

Answer 3

the force that is applied by the lever system.

Question 4

Effort

Answer 4

the force that is applied by the user of the lever system.

Question 5

Mechanical advantage

Answer 5

a large load can be lifted with a relatively small amount of effort (applies to first and second class levers).

Question 6

Mechanical disadvastage

Answer 6

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.

Question 7

Different classes of levers

Answer 7

First class
Second class
Third class

Question 8

How to remember

Answer 8

First class -Fulcrum in the middle
Second class-load in the middle
Third class-effort in the middle

Question 9

First class lever example

Answer 9

E.g when moving your head up and down the fulcrum in the middle.In a first class lever, the fulcrum sits in the middle, between the load and the effort.

Question 10

First class lever exmaple

Answer 10

In the body there is not many first class levers so few exercises use them. The main example of an exercise that uses a first class lever is a tricep dip. In this example, the elbow is the fulcrum which sits between the load (weight held in the hand) and the effort applied by the tricep.

Question 11

Second class lever example

Answer 11

In physical activity and sport, second class levers are also quite rare as they are less common in the body. A calf raise is an example of a second class lever movement. 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.

Question 12

Third class lever example

Answer 12

In a third class lever, the effort is applied between the fulcrum and the load.In the body most of the levers are third class. This is because the effort is applied between the fulcrum and the load. When you do a biceps curl, you are using a third class lever as the effort is applied by the biceps muscle, which is between the fulcrum at the elbow joint and the eight in your hands.