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