الأسبوع 16 · المحور الثالث «حماية كوكبنا»، الوحدة الثالثة «الطاقة والوقود»: ابدأ، المفهوم 3.1 «الأجهزة والطاقة» (أ) · 3 دروس
3
Toy cars, rovers and batteries
Discovery Education Science P4: Term 2, Unit 3, pp. 1–10
GoalSay where everyday devices get their energy, and write questions about energy for devices.
New words
energy source · where the energy for a device comes frombattery · a container that stores chemical energy and gives electrical energyremote-controlled · controlled from far away without wires
Explanation
Every device needs an energy source. A remote-controlled toy car gets its energy from batteries inside it. A bedside lamp gets electrical energy through a plug from the mains. A solar calculator gets energy from light. A bicycle gets it from the rider’s muscles, which got it from food. A car gets it from petrol. Now think of a robot rover on Mars, far from any shop or socket. It cannot use ordinary batteries forever. It needs an energy source that it can carry or collect. So how can light from the Sun power a phone? What kinds of energy change must happen? To start, we write questions that begin “I wonder…” and list the devices we use with their energy sources.
Device
Energy source
remote-controlled car
batteries
table lamp
mains electricity
solar calculator
light
bicycle
rider’s muscles (from food)
car
petrol
Worked examples
Omar’s remote-controlled car stops moving. The batteries are empty. The car needs a new energy source: fresh batteries or a charger, which a grown-up helps to use.
Jana sorts eight devices by energy source. 3 run on batteries, 3 plug into the mains and 2 run on sunlight. 3 + 3 + 2 = 8 devices in all.
Mina writes three “I wonder” questions. I wonder how a phone gets energy from the Sun. I wonder what a rover does at night. I wonder why a battery gets empty.
Class activity
Device list. With a grown-up, list eight devices you use in a week. Next to each write its energy source: battery, mains, sunlight, muscles or fuel. Count how many there are of each. Write three “I wonder” questions about them. Never put a finger or any object in a socket.
Practice
1
Where does a pocket torch get its energy?
From batteries inside it.
2
Which device runs on the energy of sunlight? Say the letter.
Letter
Device
A
table lamp
B
solar calculator
C
kettle
B, the solar calculator.
3
A class has 5 devices on batteries, 4 on the mains and 1 on sunlight. How many devices?
5 + 4 + 1 = 10 devices.
4
Why can a rover far from home not rely on ordinary batteries only?
There is no socket or shop near it, so it needs an energy source it can collect or carry.
