SolveItClass 9 · NCERT

NCERT Solutions · Class 9 Social Science Atmosphere and Climate

20 questions · 20 still being checked

Think About It 3.1–3.3 (part 5 of 6)

  1. Exercise 3.1

    Can you imagine what would happen if there were no atmosphere? Discuss your thoughts with your friends and teachers.NCERT_Question_Class9_SocialScience_Ch3_TAI_Q3-1

    The book prints no answer for this

    NCERT publishes no answers for this textbook, so there is nothing in the book to check this working against. It has also not yet been read through by hand.

    Without an atmosphere, life on the Earth would not be possible at all.
    Nothing to breathe — nitrogen and oxygen, the two gases essential to life, would be gone.
    No shield — the Sun's harmful radiation, including ultraviolet radiation, would strike the surface directly, because there would be no ozone layer in the stratosphere to filter it.
    No temperature control — the atmosphere traps some of the Sun's energy and stops it escaping into space, so without it the Earth could not regulate its temperature.
    No weather and no clouds — rainfall, fog, hail and wind all need air, water vapour and air pressure in the troposphere.
    Meteorites would hit the ground — today most of them burn up in the mesosphere.
    The book asks you to discuss this with friends and teachers, so take these five points into the discussion and add your own.

  2. Exercise 3.2

    You might have noticed that sometimes the wind is so strong that it is difficult to walk against it. Can you think of some other times when strong winds have caused problems for you?

    The book prints no answer for this

    NCERT publishes no answers for this textbook, so there is nothing in the book to check this working against. It has also not yet been read through by hand.

    What this asks for
    Your own memory of times when strong wind caused trouble, told in a few sentences and shared in class.
    A worked example (an example only — write your own)
    "During a pre-monsoon storm the wind uprooted a tree in our street and it fell across the road, so the buses stopped for a whole morning. The power went off because a wire snapped, and the tin sheet over our cycle stand rattled loose."
    What a good answer must contain
    The occasion and the season — a storm, a dust storm before the rains, a windy day at the coast.
    What the wind actually did — blew dust, made umbrellas useless, swayed large branches, uprooted trees.
    Who was affected and how — school closed, crops flattened, a journey cancelled.
    If you can, match the effect to a speed band in Table $\displaystyle 3.1$: large branches sway and umbrellas are hard to use in a strong breeze ($\displaystyle 39$–$\displaystyle 49$ km/hr); widespread damage comes with a storm ($\displaystyle 103$–$\displaystyle 117$ km/hr).

  3. Exercise 3.3

    Hindustani Classical music associates certain rāgas with specific seasons. Find out which rāgas are connected to each season with the help of your elders and teachers.

    The book prints no answer for this

    NCERT publishes no answers for this textbook, so there is nothing in the book to check this working against. It has also not yet been read through by hand.

    What this asks forNCERT_Solution_Class9_SocialScience_Ch3_TAI_Q3-3
    Find out from your elders and teachers which rāgas of Hindustani Classical music belong to which season, and write the pairs down.
    Start from the book's own list
    The chapter prints no rāga names. What it does give you is Table $\displaystyle 3.2$, the six traditional seasons: Vasanta, Grīṣhma, Varṣhā, Śharad, Hemanta and Śhiśhira. Use these as the rows of your table.
    A worked example of one row (an example to confirm with a music teacher — the book does not say this)
    Season (Ṛtu)MonthsRāgaWho told me
    VarṣhāŚhrāvaṇa–Bhādrapada (July–August)rāgas of the Malhār family, sung in the rainsmy music teacher
    What a good answer must contain
    One row for each of the six seasons, with the Indian-calendar months copied exactly from Table 3.2.
    The name of the person who told you, because this is knowledge passed on by people.
    If you can, one song or one line you actually heard.
    Do not copy a list you cannot check with a person or a music book.