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UNIT:8”MACHINES” ►MACHINES Machines are devices which use the action of force or convert one tyoe of Energy into another. For,example, a bicycle is machine which transforms human energy into Mechanical energy. Machines save us time and physical effort.

►Types of machines Some machines, such as pulleys, are very simple because they have very few components.Other machines, such as computers, are comlex because they have many components.. Machines can be classified depending on the energy source.there are machines which work with: Human energy, such as a bicycle or a hammer ● Water or wind , such as watermill or a windmill ● Fuch ,as a car or a gas stove ● Electricity , such as a washing machine or a mobile phone ●

*Machines which produce movement Many machines produce movement, such as escalators , cars or food blenders.these machines have a motor or an engine.The motor coverts fuel or electrical energy into movement.

*Thermal machines

Thermal machines , such as heaters and air conditioners, produce heat or cold.

*Information-processing machines Information-processing machines are used for communication and calculations.For example , we can communication with others using mobile phones,and we can make calculations, on computers.