by Tiwari Academy Team
NCERT Solutions for Class 4 EVS Our Wondrous World Chapter 7 How Things Work – exercises question answers for session 2026-27. These solutions provide clear, step-by-step answers to every activity and question in this chapter. Following Meera and Dhruv’s curiosity about spinning coins and floating paper boats, the chapter helps students explore how spinners work, why some objects spin better than others and what makes things float or sink in water. Through hands-on activities like making spinners from cardboard, testing objects like nails and stones in water and building boats from different materials, students discover that shape matters just as much as weight.
NCERT Class 4 EVS Our Wondrous World Chapter 7 Solutions
Page 105 – Activity 1
1. Do you think all objects can spin? Make a list of a few objects that can spin.
Answer:
No, I do not think all objects can spin. Some objects that can spin are a top, a wheel, a fan, a spinning toy and a coin.
2. Collect the objects mentioned in the table given below. Spin and observe them. Then, complete the table.
Answer:
Page 106 – Activity 2
Collect things, such as pieces of cardboard, toothpicks, an empty tube of a ballpoint pen, and other small objects. Make the following spinners. Spin them and record your observations.
Answer:
Page 108 – Discuss
1. Which of the spinners did not spin properly? Discuss the possible reasons.
Answer:
The second spinner did not spin properly because its hole was not at the centre. This made the spinner unbalanced.
2. Have you noticed the position of the hole in the first two spinners? Did this difference in the position of the hole make a difference in the spinning of these spinners?
Answer:
Yes, the hole in the first spinner is near the centre, while the hole in the second spinner is away from the centre. This difference affected the spinning because the second spinner was not balanced.
Page 110 – Activity 3
Collect objects, such as a leaf, an iron nail, an empty bowl (katori), a plastic bottle with a lid, pieces of stone, aluminium foil and other things of your choice. Fill a bucket with water.
Before dropping the things listed in the table, guess whether things will float or sink. You may try other things too. Then, observe what happens when it is actually dropped in water. You can write โFโ for objects that float and โSโ for objects that sink.
Answer:
Page 111 – Discuss
Did all the light objects float and all the heavy objects sink? Name the heavy objects that floated and lighter objects that sank.
Answer:
No, all the light objects did not float and all the heavy objects did not sink. The empty steel bowl and the empty bottle with a closed lid were heavy objects that floated. An iron nail or pin was a light object that sank.
Page 112 – Activity 4
Let us find out whether shape plays a role in floating and sinking.
Answer:
Page 115 – Let Us Reflect
1. Enquire about something
When Ravi spins a spinner, he notices that it slows down and eventually stops. He is curious about this and asks his teacher some questions. List at least two questions that he could ask.
Answer:
1. Why does the spinner slow down and eventually stop?
2. What makes the spinner stop after spinning for some time?
2. Figure it out
(a). The following figure is bending towards the side ‘A’. What should be done to balance it?
Answer:
To balance the figure that is bending towards side ‘A’, we should add some weight to side ‘B’ or remove some weight from side ‘A’. This will help distribute the weight evenly and make the figure balanced.
(b). How would you make a floating object sink and a sinking object float?
Answer:
To make a floating object sink: We can change its shape (like making aluminum foil into a tight ball), add weight to it, or fill it with water (like filling an empty bottle with water).
To make a sinking object float: We can change its shape to trap more air (like spreading out aluminum foil or making it cup-shaped), attach it to something that floats, or hollow it out to make it lighter.
3. Do an activity
Classify the objects below based on whether they float or sink in water.
Wax, Marble, Thermocol, Candle, Coin, Cork, Leaf, Eraser, Spoon, Ice-cube, Potato, Tomato, Pumpkin, Lemon
Answer:
Class 4 EVS Chapter 7 Question Answers with Important Extra Questions
