UNIT 8 “MACHINES� >Machines Machin are devices wich use the action the action of a force or convert one type of Energy into another. For example , a bicyclete is a machine which transfotms 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 complex 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 a watermill or a windmill -Fuel,such 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 bleders.These machines have a motor or an engine. The motor converts 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 communicate with others using mobile phones , and we can make calculations on computers.