Soc 20 - Lever Systems

Question 1

What does a ‘lever’ refer to?

Answer 1

A system of muscles and bones working together to bring about movement.

Question 2

What do your muscles do to your bones when exercising?

Answer 2

The muscles pull on the bones and the bones create movement which act as levers.

Question 3

How many components does a lever structure have?

Answer 3

4 components

Question 4

What are the four lever structure components?

Answer 4

The fulcrum, a load, an effort and a lever arm

Question 5

What is the fulcrum?

Answer 5

It is a point around which the lever rotates (joints)

Question 6

What is a load?

Answer 6

The force that is applied by the lever system. The load is the object you want to move (dumb bell with your arm)

Question 7

What is an effort?

Answer 7

A force that is applied by the user of the lever system. Effort is supplied by your muscles

Question 8

What is the lever arm?

Answer 8

A rigid bar such as a bone

Question 9

How many classes of levers are there?

Answer 9

There are three classes of levers.

Question 10

What are the three classes of levers?

Answer 10

First class, second class and third class lever

Question 11

What is a first class lever?

Answer 11

Where the fulcrum is in the middle.

Question 12

What is a second class lever?

Answer 12

Where the load is in the middle.

Question 13

What is a third class lever?

Answer 13

Where the effort is in the middle.

Question 14

What is an example of a first class lever in your body?

Answer 14

The joint between your skull and the first vertebrae

Question 15

What is an example of a second class lever in your body?

Answer 15

Your heel joint

Question 16

What is an example of a third class lever in your body?

Answer 16

Your elbow joint

Question 17

What exercise is an example of a second class lever? Where are the lever systems

Answer 17

Calf raises. The load is the body weight. The ball of the feet is the fulcrum. The gastrocnemius is the effort

Question 18

What is an example of a third class lever? Where are the lever systems?

Answer 18

Bicep curl. Load is weight in your hands. Effort applied by bicep muscle. Fulcrum is the elbow joint.

Question 19

What is an example of a first class lever? Where are the lever systems?

Answer 19

Head a football. Fulcrum is the neck. Weight of head is load. Effort is from neck muscles

Question 20

What are advantages of first class levers?

Answer 20

They are stable, strong and increasing the length of lever arm increases mechanical advantage

Question 21

What are disadvantages of a first class lever?

Answer 21

They are slow and have limited flexibility

Question 22

What are advantages of second-class levers?

Answer 22

They are stable, strong and increasing the length of lever arm increases mechanical advantage

Question 23

What are disadvantages to second-class levers?

Answer 23

They are slow and have limited flexibility

Question 24

What are advantages to third class levers?

Answer 24

They have fast movement, have large range of motion and increasing the length of lever arm increases mechanical advantage

Question 25

What are disadvantages to third class levers?

Answer 25

The force applied must always exceed the load