A simple machine is a basic mechanical device that helps multiply force, change the direction of a force, or make work easier — without using engines or electricity.
They do not create energy. They only transform how energy is used, making work more efficient by changing:
the magnitude of force
the direction of force
or the distance over which force is applied
🧠 Scientific Foundation: Work, Energy, and Force
Before we go into machines, we must understand:
Work = Force × Distance (when force moves an object)
Energy = the ability to do work
Force = a push or pull acting on an object
A machine allows us to do the same amount of work but with less effort or in a smarter way.
🧰 The 6 Classical Simple Machines
These machines were studied deeply by scientists like Archimedes, Galileo, and Newton, and they are the foundation of mechanical physics.
1. The Lever
A lever is a rigid bar that rotates around a fixed point called the fulcrum.
You apply a force (effort) at one point
The load is at another point
Fulcrum is the pivot point
The science behind it:
Law of the Lever:Effort × Effort Arm = Load × Load Arm
👉 This means you can lift heavy things by increasing the distance from the fulcrum.
Types of Levers:
Class 1: Fulcrum in the middle (like seesaw)
Class 2: Load in the middle (like wheelbarrow)
Class 3: Effort in the middle (like tongs or your arm)
2. The Inclined Plane
An inclined plane is a flat surface set at an angle.
It reduces the force needed to raise objects by increasing the distance over which the force acts.
Scientific idea:Using an inclined plane doesn’t reduce the work, but spreads it over more distance, reducing the effort force needed.
3. The Wedge
A wedge is just two inclined planes put together to form a sharp edge.
It changes the direction of force. When you push down on a wedge, it pushes materials apart sideways.
Examples:
Axe
Knife
Chisel
Wedges multiply force — they increase pressure by reducing the area of contact.
4. The Screw
A screw is a twisted inclined plane. It's an inclined plane wrapped around a cylinder.
It converts rotational force (torque) into linear motion.
Examples:
Bottle caps
Vices
Jack screws
The smaller the spacing between threads, the easier it is to turn — but the longer it takes.
5. The Wheel and Axle
This is a circular lever. The wheel is attached to a smaller axle, and both rotate together.
When you apply force to the wheel, the axle turns with more force but less distance.
Used in:
Cars
Rolling carts
Door knobs
It reduces friction and allows for easy rotational movement.
6. The Pulley
A pulley is a wheel with a groove where a rope can sit.
It changes the direction of force and can reduce effort if multiple pulleys are used (pulley systems).
In physics:
Single fixed pulley changes direction only.
Moveable pulley reduces force.
Compound pulley (block and tackle) gives both benefits.
🧮 Mechanical Advantage (MA)
Every simple machine has a mechanical advantage — how much it multiplies your effort.
MA = Load / Effort
Or
MA = Distance moved by effort / Distance moved by load
If MA > 1 → the machine multiplies force
If MA = 1 → the machine changes direction only
If MA < 1 → the machine increases speed or distance, but not force
⚙️ Efficiency
No machine is 100% perfect. Some energy is lost as heat or friction.
Efficiency = (Useful Work Output / Work Input) × 100%
Simple machines are the basis of all modern machines, but real machines (like cars or cranes) always combine several of these with energy sources.
🧩 Final Summary (Scientific Core):
Simple machines help by changing force, direction, or distance of applied effort.
They don’t create energy but allow the same work to be done more easily.
The six classical simple machines are: Lever, Inclined Plane, Wedge, Screw, Wheel & Axle, and Pulley.
Their operation is based on Newtonian mechanics and energy conservation.
Understanding them is key to designing all kinds of complex machines today.
What is your observations? or a new findings?
Did you find any special in this?
Where is your note?