Soc: 20 Lever Systems

Question 1

What is a lever?

Answer 1

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

Question 2

How many components does a lever have?

Answer 2

4

Question 3

What does a fulcrum mean?

Answer 3

A pivot or point around which the lever rotates.

Question 4

What does a load mean in a lever system?

Answer 4

The force that is applied by the lever system. The load is the object that you want to move,e.g, a dumbbell with your arm.

Question 5

What is effort in a lever system?

Answer 5

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

Question 6

What is the lever arm in a lever system?

Answer 6

A rigid bar such as a bone.

Question 7

How many different classes of levers are there?( name them)

Answer 7

3
First class
Second class
Third class

Question 8

Where are the parts of the lever system in a first class lever?

Answer 8

Fulcrum-middle
Load- left side
Effort- right side

Question 9

Where are the parts of the lever system in a second class lever?

Answer 9

Load- in the centre
Fulcrum- right side
Effort- left side

Question 10

Where are the parts of the lever system in a third class lever?

Answer 10

Effort- in the centre
Fulcrum- left side
Load- right side

Question 11

Give an example of a first class system and what is what?

Answer 11

Trciep dip:

Fulcrum- The elbow
Load- Weight held in hand
Effort- Applied by the tricep

Question 12

Give an example of a second class system and what is what?

Answer 12

Calf raise (standing on tippy toes):

Load-Body weight
Fulcrum- Ball of the feet
Effort- Force applied by gastrocnemius muscles (by pulling the heel).

Question 13

Give an example of a second class system and what is what?

Answer 13

Bicep curl:

Fulcrum- Elbow joint
Load- Dumbbell in your hands
Effort- bicep muscle

Question 14

What is a mechanical advantage?

Answer 14

When the output of the lever is greater than the input (load is greater than effort)- getting more out than you put in.

Question 15

What types of levers are an example of a mechanical advantage?

Answer 15

First and second class levers

Question 16

What is a mechanical disadvantage?

Answer 16

This is the opposite of mechanical advantage. The input is greater than the output. The force you apply is greater than the load so you are putting more in than you are getting out.

Question 17

What types of levers are an example of a mechanical disadvantage?

Answer 17

Third class levers