Practicing with Our Wondrous World Class 5 Solutions Chapter 7 Energy How Things Work Class 5 Questions and Answers improves a student’s confidence in the subject.
Class 5 EVS Chapter 7 Energy How Things Work Question Answer
Energy How Things Work Class 5 EVS Question Answer
Our Wondrous World Class 5 EVS Chapter 7 Question Answer – Class 5 EVS Energy How Things Work Question Answer
Page 114
Question 1.
Let us observe a kitchen for some time. Write your observations and the questions that come to your mind in the table given below.
Answer:
| I Observe | I Wonder |
| The food is getting cooked. | How is it being cooked? |
| Water is boiling in a vessel. | Why does water turn into steam? |
| The gas stove is burning. | What energy is used to light’the stove? |
| The pressure cooker is whistling. | How does the pressure cook food faster? |
| Vegetables are being chopped. | Why do we cook vegetables before eating? |
Page 115
Question 1.
From your observation, write down at least three things that you have noticed.
- Moving
- Providing light
- Making a sound
- Making things cool
- Making things hot
Answer:
Three things I have noticed are as follows
- Moving Fan, car, bird flying
- Providing light Sun, torch, electric bulb
- Making a sound Drum, bell, radio
- Making things cool Fridge, cooler, air conditioner
- Making things hot Gas stove, electric heater, sunlight
Page 115 Discuss
Question 1.
What makes these things move, shine, make a sound or get warm and cold?
Answer:
Energy makes things move, shine, make sound or change temperature.
For example
- The Sun gives us light and heat.
- Electricity helps fans move and bulbs shine.
- Gas makes things hot for cooking.
- Batteries give power to toys and torches.
All these are different forms of energy.
Page 116 Activity 1
1. Take a balloon and blow into it until it fills up.
2. Hold it tightly.
3. Then, release the mouth of the balloon and observe what happens.
When air rushes out of the balloon, it pushes the balloon forward. This is how the movement of air generates energy.
Extension Activity: Balloon Air Rocket
1. Fill the balloon with air and attach it to a small and light object to make it move.
2. Fill the balloon with air and attach it to a straw with tape. Pass a string through the straw Now, release the balloon and watch it move along the string.
Answer:
Do it yourself
Page 116 Think
Question 1.
What would you change in the activity to make the toy move faster or slower?
Answer:
To make the toy move faster, I would
- Blow more air into the balloon so it has more force.
- Use a lighter object so it can move quickly.
- Make sure the string is tight and smooth to reduce friction.
To make the toy move slower, I would
- Blow less air into the balloon.
- Use a heavier object.
- Use a loose or rough string that creates more resistance.
Page 117 Activity 2
Question 1.
Rubber Band Guitar
1. Make a hole on the top of a cardboard box.
2. Stretch rubber bands around the box and across the hole.
3. Place the a ruler or pencil under bands at one end to raise them.
4. Pluck the bands and listen to the sounds produced.
Plucking the rubber bands makes them vibrate and produce sounds. This is known as sound energy.
Answer:
Do it yourself
Page 117 Think
Question 1.
What happens if you use thinner or thicker rubber bands? Do they sound different?
Answer:
Yes, they sound different.
- Thinner rubber bands make a higher-pitched sound.
- Thicker rubber bands make a lower-pitched sound.
This is because the thickness of the band changes how fast it vibrates. Faster vibrations = higher sound; slower vibrations = deeper sound.
Page 117 Activity 3
1 Sun-powered Water Warmer
1. Fill two cups with water.
2. Place one cup in the sunlight and another in the shade.
3. Wait for 15-20 minutes and then touch the water in both the cups. What do you notice?
The water kept in the sunlight is warmer because the Sun heats it up. This shows how the sunlight gives us heat energy.
Answer:
Do it yourself
Page 119 Think
Question 1.
What do cars and scooters need to keep running?
Answer:
Cars and scooters need fuel like petrol or diesel to keep running. Fuel gives them energy to move.
Page 119 Write
Question 1.
How is food cooked in your house?
Answer:
In my house, food is cooked using cooking gas (LPG) on a gas stove.
Page 120 Discuss
Question 1.
What kind of fuel do you use at home for cooking?
Answer:
We use LPG (Liquefied Petroleum Gas) at home for cooking.
Question 2.
What are the problems using too much wood or coal?
Answer:
Using too much wood or coal creates smoke and air pollution. It can also cause health problems and harm the environment.
Page 120 Activity 4
Question 1.
Understanding How Fuel Works
1. Place two diyas (lamps) on a flat surface.
2. In Diya 1 – place a cotton wick without any oil and in Diya 2 – place a cotton wick and pour some oil around it.
3. Light the wicks in both the diyas under adult supervision.
4. Observe what happens to the diyas.
(a) Which diya burns longer? Why?
(b) What is acting as a fuel here?
Answer:
Do it yourself
Page 121 (Electricity)
Question 1.
What are the things in your home that need electricity to work?
Answer:
Many things in my home need electricity to work, such as
- Fan – to keep the room cool
- Tube light/Bulb – to give us light
- TV – to watch cartoons and news
- Refrigerator – to keep food fresh and cold
Page 121 Activity 5
Question 1.
Walk around your home or classroom. Identify five things that run on electricity. Fill in the following table.
Answer:
Page 122 Think
Question 1.
What would your day be like if there was no electricity at all?
Answer:
If there was no electricity at all, my day would be very difficult.
- I would not be able to use the fan or light, so it would be hot and dark.
- There would be no TV or mobile phone, so I couldn’t watch cartoons or call anyone.
- Refrigerator would not work and food could get spoiled.
Page 123 Think
Question 1.
Place a small damp cloth in the Sun. Keep another damp cloth in the shade. Which one do you think will dry first? Why?
Answer:
The cloth kept in the Sun will dry first because the Sun gives heat, which helps water evaporate faster than in the shade.
Page 123 Activity 6
Question 1.
Pinwheel
1. Take a square piece of paper.
2. Draw its two diagonals with the help of a ruler.
3. Now, you have four equal parts.
4. Cut halfway along each of the four lines.
5. Fold each corner and pin it to the stick as shown in the image.
6. Now, hold your pinwheel in the wind. If there is no wind, hold it up and run with it.
Answer:
Do it yourself.
Question 2.
What happens to your pinwheel?
Answer:
When I hold the pinwheel in the wind or run with it, the blades spin quickly. This happens because the moving air (wind) pushes the blades and makes them rotate.
Page 124 Activity 7 and 8
Sunlight in Focus
1. Take a piece of paper and a magnifying glass.
2. Place the paper in direct sunlight and use the magnifying glass to focus the light on it.
Tip The activity has to be done under adult supervision.
Answer:
Do it yourself
Question 1.
What happens to your paper?
Answer:
When we focus sunlight on the paper using a magnifying glass, the paper starts to burn or gets a black spot. This shows that sunlight has heat energy.
Water Wheel
1. Take an empty paper cup and five spoons.
2. Make five holes around the cup and insert the spoons.
3. Then, insert a pencil or straw through the bottom of the cup.
4. Observe that the cup moves around the pencil like a wheel.
5. Balance your wheel on a container as shown in the image.
6. Now, pour water onto your wheel.
Answer:
Do it yourself
Question 2.
Does the water make the wheel move?
Answer:
Yes, when water is poured on the spoons, it pushes them and makes the cup spin like a wheel. This shows that moving water has energy and can do work.
Page 125 Think
Question 1.
Have you ever seen papads being dried in the sunlight and clothes hung out to dry?
Answer:
Yes, I have seen papads being dried in the sunlight and clothes hung out to dry.
Page 125 Write
Question 1.
Can you think of more examples where we use the Sun, the wind or the flowing water?
Answer:
Other examples where
We use the Sun for
- Drying clothes and papads
- Making solar electricity with solar panels We use the Wind for
- Flying kites
- Running windmills to make electricity
We use Flowing Water for
- Making electricity in dams
- Watering crops in farms
Page 127 Write
Question 1.
List actions that you see in the picture below and fill in the following table
Answer:
| Activity | Source of Energy |
| A child carrying a school bag | Food |
| A car moving on the road | Petrol or diesel |
| Clothes drying on a clothesline | Sunlight |
| A plane flying in the sky | Aviation fuel |
| A train running on the track | Electricity or diesel |
Page 128 Activity 9
Question 1.
Energy Flow Game
Prepare paper slips with names or pictures of energy sources: the Sun, wind, water, food, fuel and electricity.
The second paper slips should indicate types of energy, like heat, light, movement and sound.
The last paper slips should contain the uses or examples of where this energy is used – drying clothes, lighting a bulb, turning a turbine, cooking, running, etc.
Step 1: Assigning a Role
Give each student one card, where they will either be:
A source of energy (the Sun, wind, etc.)
Type of energy (heat, light, etc.)
Use (for example, helps plants grow, moves a car, etc.)
Step 2: Walk Around and Find Your Match
Students should walk around the class trying to find the two others who complete their energy chain.
For example
Sun →Heat → Helps dry clothes
Wind → Movement → Turns turbine to make electricity
Step 3: Present to Class
Once matched (source – type – use), each group should quickly explain their match to the class, for example, “We are the heat of the Sun and we help to dry clothes
Answer:
Do it yourself
Page 130 Let us reflect
Question 1.
What will happen if there is no electricity in your house for a day?
Answer:
If there is no electricity in your house for a day there will be no light, fan or TV. Food in the fridge may spoil. We cannot charge phones or use machines. Everything will feel difficult.
Question 2.
Why is it better to use solar or wind energy instead of coal?
Answer:
It is better to use solar or wind energy instead of coal because they are clean and do not pollute the air. Coal creates smoke and pollution which is not good for the environment and health.
Question 3.
Give two examples where you have seen energy being stored.
Answer:
Two examples where I have seen energy being stored are:
- In a battery, energy is stored for toys or torch.
- In a power bank, energy is stored to charge mobiles.
Question 4.
What is the one thing you can do at home to save energy?
Answer:
To save energy at home I can turn off lights, fans and TV when not in use.
Question 5.
Find out how many kilometres a vehicle travels per litre of petrol or diesel. Ask about different vehicles. How will you compare them?
Answer:
- A scooter travels about 40-50km per litre.
- A car travels about 15-20km per litre.
We can compare them by checking which one travels more distance using the same amount of fuel.
Question 6.
Look around your home or classroom. List any three objects that use energy and mention their source of energy.
Answer:
| Object | Energy Source |
| Bulb | Electricity |
| Gas Stove | LPG (Gas) |
| Mobile Phone | Battery (Charged with electricity) |
Question 7.
Create and Share
(a) Draw or make a simple plan of a ‘clean energy home’
(b) Make ‘my energy diary’ for one day
Answer:
(a) Draw a house with solar panels on the roof, a windmill nearby and LED lights inside. Mention “No smoke, no coal” for clean energy.
(b)
- I used fan – 6 times
- Lights – 4 times
- TV – 2 times
- Charger – 3 times