CHAPTER 1: LEVERS, LINKAGES AND
GEARS (PART 1)
CHAPTER OVERVIEW
Machines are made up of different parts called mechanisms. These mechanisms make work
easier by helping us move objects with less effort, over greater distances or at higher speeds.
In this chapter you will learn:
• What mechanisms are. • What a lever is. • What mechanical advantage means. • What
distance advantage means. • How to calculate mechanical advantage. • Why some levers make
work easier while others make movement faster.
This chapter forms the foundation for understanding many tools and machines used every day.
1. MECHANISMS
What is a mechanism?
A mechanism is a part of a machine that creates or controls movement.
Machines usually consist of several mechanisms working together.
Some parts of a mechanism move, while other parts hold everything in place.
Examples:
● Bottle opener
● Scissors
● Hammer
● Pliers
These mechanisms help us:
, ● Lift heavy objects.
● Cut materials.
● Pull objects apart.
● Make difficult jobs easier.
Why are mechanisms useful?
Mechanisms help us to:
• Use less force. • Move objects further. • Move objects faster. • Change the direction of
movement. • Make work easier and more efficient.
2. LEVERS
A lever is one of the simplest types of mechanisms.
It is a rigid bar that rotates around a fixed point called a fulcrum.
Every lever has:
• An input force • An output force • A fulcrum (pivot point)
Levers can:
● Increase force.
● Increase distance moved.
● Change the direction of movement.
3. MECHANICAL ADVANTAGE (MA)
What is Mechanical Advantage?
Mechanical Advantage (MA) tells us how much a machine increases or decreases force.
It compares:
,Output Force ÷ Input Force
Formula:
Mechanical Advantage = Output Force ÷ Input Force
Abbreviation:
MA
Understanding the Formula
Imagine:
Input Force = 5 N
Output Force = 15 N
MA = 15 ÷ 5
MA = 3
This means:
The machine makes your force three times bigger.
You only apply a small force, but the machine produces a much larger force.
What does MA tell us?
If MA is greater than 1
Example:
MA = 2
MA = 3
MA = 5
This means:
, • Small input force • Large output force • The machine makes work easier
This is called a mechanical advantage.
If MA equals 1
Input force = Output force.
The machine changes the direction of movement but does not increase force.
If MA is less than 1
Example:
MA = ½
MA = ⅓
MA = ¼
This means:
• Large input force • Small output force
The machine does not make work easier.
Instead, it gives a distance advantage.
4. DISTANCE ADVANTAGE
Sometimes a machine sacrifices force to gain movement.
Instead of making lifting easier, it allows something to move much further or much faster.
This is called a distance advantage.
Example:
Kitchen tongs.
GEARS (PART 1)
CHAPTER OVERVIEW
Machines are made up of different parts called mechanisms. These mechanisms make work
easier by helping us move objects with less effort, over greater distances or at higher speeds.
In this chapter you will learn:
• What mechanisms are. • What a lever is. • What mechanical advantage means. • What
distance advantage means. • How to calculate mechanical advantage. • Why some levers make
work easier while others make movement faster.
This chapter forms the foundation for understanding many tools and machines used every day.
1. MECHANISMS
What is a mechanism?
A mechanism is a part of a machine that creates or controls movement.
Machines usually consist of several mechanisms working together.
Some parts of a mechanism move, while other parts hold everything in place.
Examples:
● Bottle opener
● Scissors
● Hammer
● Pliers
These mechanisms help us:
, ● Lift heavy objects.
● Cut materials.
● Pull objects apart.
● Make difficult jobs easier.
Why are mechanisms useful?
Mechanisms help us to:
• Use less force. • Move objects further. • Move objects faster. • Change the direction of
movement. • Make work easier and more efficient.
2. LEVERS
A lever is one of the simplest types of mechanisms.
It is a rigid bar that rotates around a fixed point called a fulcrum.
Every lever has:
• An input force • An output force • A fulcrum (pivot point)
Levers can:
● Increase force.
● Increase distance moved.
● Change the direction of movement.
3. MECHANICAL ADVANTAGE (MA)
What is Mechanical Advantage?
Mechanical Advantage (MA) tells us how much a machine increases or decreases force.
It compares:
,Output Force ÷ Input Force
Formula:
Mechanical Advantage = Output Force ÷ Input Force
Abbreviation:
MA
Understanding the Formula
Imagine:
Input Force = 5 N
Output Force = 15 N
MA = 15 ÷ 5
MA = 3
This means:
The machine makes your force three times bigger.
You only apply a small force, but the machine produces a much larger force.
What does MA tell us?
If MA is greater than 1
Example:
MA = 2
MA = 3
MA = 5
This means:
, • Small input force • Large output force • The machine makes work easier
This is called a mechanical advantage.
If MA equals 1
Input force = Output force.
The machine changes the direction of movement but does not increase force.
If MA is less than 1
Example:
MA = ½
MA = ⅓
MA = ¼
This means:
• Large input force • Small output force
The machine does not make work easier.
Instead, it gives a distance advantage.
4. DISTANCE ADVANTAGE
Sometimes a machine sacrifices force to gain movement.
Instead of making lifting easier, it allows something to move much further or much faster.
This is called a distance advantage.
Example:
Kitchen tongs.
