📘 Class 5 EVS
Book: Our Wondrous World
Unit 4 – Things Around Us
Chapter 7: Energy — How Things Work (Pages 114–130)
⚡ What is Energy? (Pages 114–115)
In the kitchen and around us, we see many things:
- Things move
- Give light
- Make sound
- Become hot or cold
Energy is what makes all this happen.
👉 Energy makes things move, light up, make sound, do work and change temperature. (Page 115)
🧪 Activity 1 – Balloon Rocket (Page 116)
What happens?
- When air comes out, the balloon moves forward.
Answer (Think):
To make it faster → put more air or use a lighter object.
To make it slower → use less air or a heavier object.
🎸 Activity 2 – Rubber Band Guitar (Page 117)
What happens?
- Rubber bands vibrate and make sound.
Answer:
- Thin rubber band → sharp sound
- Thick rubber band → deep sound
This is sound energy.
☀️ Activity 3 – Sun-powered Water Warmer (Page 117)
What do you notice?
- Water kept in the Sun is warmer.
Conclusion:
The Sun gives us heat energy.
🍞 Sources of Energy – Food (Pages 118–119)
- We get energy from food.
- Animals also get energy from food.
- Even our brain uses energy when we think or sleep.
Write (Page 119)
How is food cooked in your house?
Answer (example):
On a gas stove using cooking gas.
⛽ Energy from Fuel (Pages 119–120)
- Vehicles use petrol and diesel.
- At home, we use cooking gas, wood or coal.
Discuss (Page 120)
- Fuel used at home: LPG / gas
- Problems of wood/coal:
- Smoke
- Pollution
- Bad for health and environment
🪔 Activity 4 – Diya Experiment (Page 120)
(a) Which diya burns longer? Why?
Answer:
The diya with oil burns longer because oil is the fuel.
(b) What is acting as fuel?
Answer:
Oil
💡 Electricity (Pages 121–122)
Electricity helps in:
- Movement (fan)
- Light (bulb)
- Sound (TV)
- Heat (iron)
Activity 5 – Examples (Page 121)
| Device | What it does | What it requires |
|---|---|---|
| Fan | Blows air | Movement |
| Bulb | Gives light | Light |
| TV | Shows sound & picture | Sound & light |
| Fridge | Keeps things cold | Cooling |
| Iron | Heats clothes | Heat |
⚠️ Safe Use of Electricity (Page 122)
- Do not touch bare wires
- Do not put things in socket
- Stay away from broken wires
- Tell adults if something is unsafe
🌍 Clean Energy vs Coal (Pages 123–126)
- Coal causes pollution.
- Clean energy comes from:
- Sun
- Wind
- Water
Activity 6 – Pinwheel (Page 123–124)
What happens?
- Pinwheel rotates because of wind energy.
Activity 7 – Sunlight in Focus (Page 124)
What happens to paper?
- It burns or becomes very hot → shows Sun’s heat energy.
Activity 8 – Water Wheel (Page 124)
Does the wheel move?
Answer:
Yes, flowing water makes it move → water energy.
✍️ Write (Page 125)
Examples of using Sun, wind or water:
- Drying clothes in Sun
- Sailing boat using wind
- Watermill grinding grains
- Solar cooker
- Windmill making electricity
🔋 Clean Energy (Page 126)
- Solar panels → sunlight to electricity
- Windmills → wind to electricity
- Dams/rivers → water to electricity
👉 This is called clean energy because it does not pollute.
🚗 Even Vehicles Can Run on Electricity (Page 127)
Energy All Around Us – Table (Page 127)
| Activity | Source of Energy |
|---|---|
| Child carrying bag | Food |
| Fan running | Electricity |
| Boat moving | Wind |
| Water wheel | Flowing water |
| Clothes drying | Sun |
🎲 Activity 9 – Energy Flow Game (Page 128)
Examples:
- Sun → Heat → Dries clothes
- Wind → Movement → Turns turbine
- Fuel → Heat → Cooks food
🌞 Important Points (Page 129)
- The Sun gives more energy in 1 hour than humans use in 1 year.
- Our body stores energy.
- Batteries also store energy.
- We should save energy and use clean energy.
🧠 Let Us Reflect – Answers (Page 130)
1. What if no electricity for a day?
Answer:
No fan, no lights, no TV, no charging. Life will be difficult.
2. Why solar/wind better than coal?
Answer:
Because they do not cause pollution and are clean energy.
3. Two examples of stored energy
Answer:
- Battery
- Our body (food energy)
4. One thing to save energy
Answer:
Switch off lights and fans when not needed.
5. Vehicle mileage comparison
Answer:
Vehicle that goes more km per litre is better.
6. Three objects and energy source
- Fan → Electricity
- Car → Petrol
- Gas stove → LPG (gas)
7. (a) Clean energy home (Answer idea)
- Solar panels on roof
- Windmill nearby
- Big windows for sunlight
7. (b) My energy diary
- Morning: light, fan
- Cooking: gas
- Evening: TV, lights, phone charging
🌟 Chapter Summary
- Energy makes everything work
- We get energy from food, fuel, electricity
- Sun, wind and water give clean energy
- We must use energy carefully and save it
