UNIT 8:”MACHINES” *Machines. Machines are devices whichn use the action of aforce or convert one type of Energy into another. For example,a bicycle is a machine which transform human energy into mechanical energy.Machine save time and physical effort.
*Types of machine Some machines,such as pulleys are very simple because they have very few components..Others machiines us computers are complex because they have many components. Machines can be clasificated depending on the energy source.There are machines which work with: ·Human energy , such as a bicicle 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. *Machine which produces movement Many machines produce movement, such as escalators,cars or food blenders.These machines have a motor or a 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.