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Simple Machines
Contents
Intro
Levers
Pulleys
Inclined Plane
Wheel and Axle
Intro
A simple machine is a mechanical device which makes effort lighter and decreases frictional force. In general, there are 6 main types of simple machines:
Levers Pulleys Wheel & Axle Wedge Screw
Levers
A lever (French word for ‘to raise’) is a simple machine which turns around a fixed point called the fulcrum. The effort is a force applied to the load.
Examples of levers are: Wheelbarrows Scissors Claw hammer
Levers
Basically, levers are classified into 3 groups.
Levers
1st Class(Small force
To move largeLoad.
2nd Class(Effort has a
LongerDistance
than load.)
3rd Class(Large force
Used toMove small
Load.)
Pulleys
• A pulley uses a small effort to carry a large load.
Fixed pulley
- Has a fixed wheel.
- Changes the direction of the force applied to the rope/belt.
Pulleys
Movable Pulley- Has free-moving wheels. - The force applied is multiplied. (Eg. 1st wheel =
50N, 2nd wheel = 50N, load = 100N – 50 x 50 = 100N)
*Note: ‘N’ represents ‘Newtons’, the unit to measure force.
Wheel and Axle
The wheel and axle is a simple machine which a small force (axle) is rotated with an outer bigger force (wheel).
Such examples are: Kitchen taps Bicycle wheels Fans
Inclined Plane
Examples:
• Mountains
• Staircases
As the load goes further, the amount of effort is increased.
Wedge
• A wedge can be used to separate two objects or a portion of one object.
• A downward force produce a perpendicular effort inclined
to the surface.
Screw
• In definition, it is an inclined plane wrapped around helically around an axis.
• When moved, the load’s effort and distance increases.
Examples:- Nail- Archimedes’ screw (a device used to lift water.)
Source: Wikipedia