UNiT:8 “MACHINES” ►Machines Machines are devices which use the action of a force or covert one type of Energy into another For examle,a bicycle is a machine which transforms human energy into Mechanical energy. Machines save us time and physycal 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 clasiffied 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 machines or a movile 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 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.With others using movile phones, and we can make calculations on computers