الأسبوع 16 · المحور الثالث «حماية كوكبنا»، الوحدة الثالثة «الطاقة والوقود»: ابدأ، المفهوم 3.1 «الأجهزة والطاقة» (أ) · 3 دروس
1
Fuels and energy around us
Discovery Education Science P4: Term 2, Unit 3, pp. 1–10
GoalName fuels people use and say what the energy from a fuel is used for.
New words
fuel · a material that is burned to release heatthermal energy · heat energycylinder · a metal container that holds gas
Explanation
A fuel is a material that releases thermal energy when it is burned. People use fuels every day. Wood and charcoal are burned in some places for cooking and warmth. Natural gas is used in kitchens, often from a pipe or a gas cylinder. Petrol and diesel are burned inside engines to move cars, buses and tractors. The energy from a fuel can be used for three main jobs: cooking, heating and moving things. Fuels also help to make electricity, which lights our homes and runs many machines. Fuels store chemical energy. When a fuel is burned, the chemical energy is released as heat and light. Fire is dangerous. Children never play with matches, lighters, gas cylinders or petrol.
Fuel
Used for
natural gas
cooking
wood and charcoal
cooking and warmth
petrol and diesel
moving cars, buses and tractors
Worked examples
Marwan’s mother cooks lunch on a gas cooker. The gas is the fuel. Its chemical energy changes into heat, and the heat cooks the food.
A farmer near the Nile uses a tractor to plough the field. The tractor burns diesel, and the engine changes the chemical energy into motion.
A class survey: 10 families say how they mainly cook. 6 use gas cylinders, 3 use a pipe from the street and 1 uses wood. 6 + 3 + 1 = 10. More families use gas than wood.
Class activity
Fuel hunt. With a grown-up, find out which fuels your family uses for cooking, for travelling and for heating water. Write them in a table: Job, Fuel. Do not touch the cooker, matches or any cylinder. Ask your grown-up: where does this fuel come from?
Practice
1
What is a fuel?
A material that is burned to release heat energy.
2
Name three jobs that the energy from fuels does.
Cooking, heating, and moving vehicles (or making electricity).
3
Which fuel does each vehicle burn? Say the letter of the one that burns petrol or diesel.
A, the car. A bicycle (B) is moved by muscles.
4
In a survey 4 families use gas, 2 use wood and 1 uses electricity. How many families were asked?
