SCIENCE FORM 5CHAPTER 5: MOTION /GERAKAN5.1Motion of vehicles on land1) There are 2 types of vehicles on land: vehicles without an engine, for example bicycle vehicles with engines, for example, cars, busses.2) Structure and principle of operation of vehicles without an engine Vehicles which do not operate by using engine use energy from human or animals to rotate their wheels. A bicycle as shown in figure below is moved with human energy.

3) Structure and principle of operation of vehicles with engines An engine is a machine that converts the chemical energy stored in a fuel into heat energy. The heat energy, which is produced from the combustion of fuels, is then converted into kinetic energy. Chemical energy heat energy kinetic energy Cars are operated by both petrol and diesel engines while heavy vehicles such as buses are run by using diesel engines. There are different types of internal combustion engines, such as a) the four stroke petrol engine ( for light vehicles such as car) b) the four stroke diesel engine ( for heavy vehicles such as buses and lorries) c) the two stroke petrol engine ( for motorcycle)

i) The four stroke petrol engine (for light vehicles such as car)

ii) The four stroke petrol engine (for light vehicles such as car)

iii) The two stroke petrol engine

Used for small machines e.g. motor boats, motorcycles. It is an inlet tube for the petrol-air mixture to go in and an outlet tube for exhaust gases to up escape. The inlet tube and the outlet tube are open or closed by the piston moving up and down.

Differences between the Four-stroke Petrol Engine and the Four-stroke Diesel Engine

Differences between the Four-stroke Petrol Engine and the Two-stroke Diesel Engine