Discover, Design and Debate — Projects — Pressure, Winds, Storms, and Cyclones

1. 14 marksCuriosity Grade 8, Chapter 6, page 97, project 1

   Hold a strip of paper 18 cm long and 2 cm wide between your thumb and forefinger so that it hangs freely. Predict what you will observe if you blow over the paper. Perform the activity, note your observations and interpret your results.

   Hint. Write the prediction down before you blow. That instruction is the point of the project.

   The prediction comes first, and it must be written down. The project says Predict what you will observe before Perform the activity now — in that order, deliberately. Most people predict the strip will be pushed down, since you are blowing downwards over the top of it. Write down whatever you honestly expect.

   What actually happens. The free end of the strip rises towards the horizontal while you blow, and falls again when you stop.

   Interpretation. Blowing over the top makes the air there move fast, and high speed winds are accompanied by a reduced air pressure (Activity 6.6). The air underneath the strip is still, so its pressure remains higher — and that higher pressure below pushes the strip up.

   ✦ This is the third form of one idea, and lining them up is the real learning:

   Situation	Fast-moving air	Still air	Result
   Two hanging balloons (Activity 6.6)	In the gap between them	Outside	They move together
   A roof in a storm (section 6.4)	Above the roof	Inside the house	The roof is pushed up
   This paper strip	Over the top	Underneath	The strip rises

   Extensions worth putting in your report: does blowing harder lift it further? What happens if you blow under the strip instead? What if you use a wider or a longer strip?

   Report the prediction even if it was wrong — especially if it was wrong. Being surprised is the evidence that you learnt something, and a report that quietly replaces the prediction with the result has thrown that evidence away.

2. 25 marksCuriosity Grade 8, Chapter 6, page 97, project 2

   List three major cyclones that have occurred in India in the last 20 years. For each, list two major forms of destruction caused. What measures did the local government and communities take to reduce loss of life and property? Suggest two things you would propose to the local government.

   Hint. This is a research project — the answers must come from sources you check, not from memory.

   This is a research task, and the answer has to be built rather than recalled. The chapter names exactly one cyclone — the Amphan cyclone in 2020 had peak wind speeds of 270 km/h — and gives no others, no dates and no casualty figures. Everything else you need has to come from a source you have actually looked at.

   Where to look. The India Meteorological Department (IMD), which the chapter names as the body that constantly monitors cyclones and thunderstorms in India; state disaster management authorities; and newspaper archives from the time. Write down the source next to each fact as you collect it.

   A table to fill in — one row per cyclone:

   	Cyclone 1	Cyclone 2	Cyclone 3
   Name and year
   States affected
   Destruction 1
   Destruction 2
   Warning and evacuation measures
   Source checked

   For the destruction column, the chapter's own list of cyclone effects tells you what to look for: storm surge and coastal flooding, rivers overflowing, landslides, contaminated drinking water, salt damage to farmland, blocked roads, and power outages lasting days.

   ✦ Be careful with casualty figures above all. Different sources give different numbers for the same cyclone, and figures are revised for years afterwards. If you quote one, name the source and the date it was published; if sources disagree, say so rather than picking the largest. A project that reports 'sources give figures between X and Y' is better work than one that states a single confident number it cannot support.

   For your two proposals, base them on what the chapter says actually helps — staying updated on IMD alerts, keeping an emergency kit ready, and having a designated cyclone shelter nearby. Proposals about warning reaching people in time, and about shelters being close enough to reach, address the parts of the problem the chapter identifies.

3. 35 marksCuriosity Grade 8, Chapter 6, page 97, project 3

   Collect data on the strength of thunderstorms for various regions of India. Compare your findings and identify which regions are more prone to thunderstorms. Can you give reasons for your findings?

   Hint. The chapter gives you a testable hypothesis before you start collecting anything.

   Start from the chapter's hypothesis, then test it. Two sentences give you something to check rather than merely a topic to describe:

   • In hot, humid, and tropical regions like India, storms are more frequent.
   • Important requirements for the formation of thunderstorms are moisture and strong winds.

   So the prediction is: regions that are hot and have plenty of moisture — coastal areas, the north-east, the Gangetic plains before the monsoon — should record more thunderstorms than dry inland regions. Write that prediction down before you look at any data.

   Where to get data. The India Meteorological Department is the source the chapter itself names. Record for each region what quantity you have found (number of thunderstorm days per year? per month?), which years it covers, and where it came from.

   A comparison table:

   Region	Measure of thunderstorm activity	Period covered	Hot?	Humid?	Source

   Reasons to look for in your findings. The chapter's A step further box already supplies part of the answer: pre-monsoon thunderstorms are frequent enough in West Bengal, Bihar and Jharkhand to have their own name (Kalboishakhi), and likewise in Assam (Bordoisila) and in Kerala, Karnataka and Tamil Nadu (mango showers). A region having its own word for a storm is itself a kind of evidence.

   ✦ Two honest cautions to build into the report.

   • Make sure you are comparing like with like. Thunderstorm counts measured over different periods, or by different methods, cannot be lined up in one table as though they were the same measurement.
   • A pattern in the data does not by itself prove the explanation. If humid regions do report more thunderstorms, that is consistent with the chapter's reasoning — it is not a demonstration of it, since those regions differ from dry ones in many other ways too. Say what your data supports, and say where you are going beyond it.

Solutions written by the tuition.in editorial team and checked against NCERT Curiosity, Textbook of Science for Grade 8, Chapter 6 'Pressure, Winds, Storms, and Cyclones', book pages 80-97 (hecu106.pdf, 18 pages, Reprint 2026-27), downloaded from ncert.nic.in and read page by page. Every activity number, figure number, quantity and quoted sentence below was checked against that PDF. THREE FIGURES WERE MEASURED, NOT EYEBALLED, because three exercise answers turn on them. Fig. 6.22 (exercise 1(iv)) was rendered at 900 dpi and the vessel walls located from the dark outlines: vessel A is 519 px wide and vessel B is 726 px, so B is 1.40x wider, while the water columns measure 660 px and 671 px - equal to within 1.7%, matching the question's premise of equal levels. Hence P_A = P_B but F_A < F_B, answer (b). Fig. 6.24 (exercise 7) was segmented by colour: the two balloons occupy identical vertical ranges (rows 1260-1403, centroids both at row 1334), so they are at exactly the same height and bulge equally. Fig. 6.25 (exercise 9) was measured by tracking the palm trunks: the leftmost trunk's centre moves from x=655 at the top to x=763 near the base, so the crown sits about 108 px LEFT of the base, and all four crowns stream leftwards - the wind blows from B to A. Since a summer afternoon gives a SEA BREEZE (sea to land), B is the sea and A is the land. Fig. 6.21 was also rendered and confirmed to show the three vessels JOINED BY TUBES near their bases, which is what makes answer (d) correct. The chapter's own atmospheric-pressure figure was checked rather than assumed: 2250 N over 15 cm x 15 cm = 0.0225 m^2 gives 1,00,000 Pa = 1000 hPa = 1000 mb, which sits squarely inside the 994-1008 mb range marked on Fig. 6.19, so the book's number is internally consistent. Two deliberate restraints. (1) The chapter names exactly ONE cyclone (Amphan 2020, peak winds 270 km/h) and one surge range (3-12 m), and gives no cyclone categories, no casualty figures, no monsoon rainfall percentages and no atmospheric composition percentages. None are supplied here; the research projects tell the student to cite IMD or an equivalent checked source and to report disagreement between sources rather than pick a number. (2) Lightning-safety advice is reproduced exactly as the book gives it, with nothing added, since an invented extra rule could put someone at risk.. Questions are referenced from the NCERT textbook for identification.