Soc 20 - Levers

Question 1

What is a lever?

Answer 1

The term ‘lever’ refers to a system of muscles and bones working together to bring about movement. When you exercise, your muscles pull on your bones, and your bones create movement, acting as levers.

Question 2

How does a lever work?

Answer 2

A lever is a structure that has four components: -
- A fulcrum - (or pivot) - the point around which the lever rotates (joints)
- 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
- An effort- a force that is applied by the user of the lever system. The Effort is supplied By your muscles
- Lever arm - a rigid bar such as a bone

Question 3

What are the different classes of levers?

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

How do you remember the different classes of levers?

Answer 4

We use the term ‘FLE’:
-First class lever - Fulcrum is in the middle
-Second class lever - Load is in the middle
-Third class lever - Effort is in the middle

Question 5

What is the fulcrum?

Answer 5

The pivot point around which the lever rotates. In your body, these are your joints.

Question 6

What is the load?

Answer 6

The force or resistance being moved, like a dumbbell or your own bodyweight.

Question 7

What is effort?

Answer 7

The force applied to move the load. This force comes from your muscles contracting.

Question 8

What is the lever arm?

Answer 8

The rigid bar that moves around the fulcrum. In your body, these are your bones.

Question 9

What type of lever system is used when performing a header?

Answer 9

When heading the ball, a first class lever system if going to be used, the fulcrum comes from your neck joint, the load comes from the weight of your head, and the effort comes from your neck muscles.

Question 10

What type of lever system is used when performing a tricep dip?

Answer 10

This is a first class lever system. The fulcrum is the elbow joint, the load is your own body weight, and the effort is from the tricep muscle.

Question 11

What type of lever system is used when performing a calf raise?

Answer 11

This is a second class lever. The fulcrum is the ball of your foot, the load is your bodyweight, the effort is your calf muscle

Question 12

How can you identify a second class lever?

Answer 12

Because the loads sits in the middle.

Question 13

What type of lever system is used when performing a bicep curl?

Answer 13

This is a third class lever system, the effort sits in the middle, between the fulcrum and the load. The fulcrum is the elbow joint, effort is your bicep muscle, load is the weight in your hand.

Question 14

What is meant by a mechanical advantage?

Answer 14

A large load can be lifted with a small amount of effort. Output is greater than input.

Question 15

What is meant by a mechanical disadvantage?

Answer 15

More effort is required to lift a load. The input is greater than the output.

Question 16

Explain why a third class lever is at a mechanical disadvantage.

Answer 16

The effort arm is shorter than the load arm, therefore mire force/effort is needed to move the load, although movement speed increases.

Question 17

Explain why the first and second class lever is at a mechanical advantage?

Answer 17

The effort arm is longer than the load arm meaning they can move a larger load with less effort