Soc 20

Question 1

What are levers

Answer 1

In your body, the term ‘lever’ refers to a system of muscles and bones working together to help you move.

Question 2

How a lever works

Answer 2

1) a fulcrum - (or pivot) - the point around which the lever rotates (joints)
2) a load - the force that is applied by the lever system. The load is the object you want to move a dumb bell with your arm
3) an effort- a force that is applied by the user of the lever system. The Effort is supplied By your muscles

Question 3

Different classes of lever

Answer 3

Levers are classified according to the placement of the fulcrum, load and effort. This affect how the levers operates.
There are three different classes of levers: - 1) first class
2) second class
3) third class

Question 4

First class

Answer 4

In a first class lever, the fulcrum sits in the middle, between the load and the effort.
A good example of a first class lever is the oar on a boat. To move the boat through the water, the rower applies effort by pulling on one end of the oar, and this applies force on the water (the load).
The main examples are exercises where the elbow or the knee straightens. Foe example the elbow in triceps extensions and tricep dips.

Question 5

Second class levers

Answer 5

In a second class leavers, the load sits between the fulcrum and effort
A wheelbarrow is a good example. The wheel is the fulcrum, the handles take the effort, and the load is placed between them.

Question 6

Third class levers

Answer 6

In a third class lever, the effort is applied between the fulcrum and the load.
A spade is a good example of a third class lever. When you use a spade, your first hand on the handle acts as the fulcrum, while your second hand applies the effort half way down the spade. Whatever the spade is picking up is the load