Chapter 2 – Motions of the Earth
EXERCISES
1. What’s the solution?
Amit wants to take his granny to Australia which is in the southern hemisphere. But she cannot bear very cold weather. When should they make this trip?
Ans: Australia is located in the southern hemisphere. During the time period of September 23 to March 22, there is summer. So Amit’s grandmother could be taken to Australia during this period. During the period of March 22 to September 23, there is winter, so she should avoid going to Australia as she cannot bear the cold weather.
2. Use your brain power !
(a) How many rotations does the earth complete during one revolution around the sun?
Ans: The earth takes one complete rotation in one day. It takes a complete 365 days ¼ and one. th day for one complete revolution. This means that in one revolution, the earth shows 365 and ¼ rotations.
(b) It is sunrise at Itanagar in Arunachal Pradesh. Write the names of the following cities in the order in which the sun will rise there.
Mumbai (Maharashtra), Kolkata (West Bengal), Bhopal (Madhya Pradesh), Nagpur (Maharashtra).
Ans:
(i) Kolkata (West Bengal)
(ii) Bhopal (Madhya Pradesh)
(iii) Nagpur (Maharashtra)
(iv) Mumbai (Maharashtra)
3. Fill in the blanks.
(a) The motion of the earth around itself is called ______.
Ans: rotation.
(b) The motion of the earth around the sun is called ______.
Ans: revolution
(c) The rotation of the earth gives rise to ______.
Ans: day and night
4. What is meant by each of the following terms?
(a) Full moon
Ans: When the complete and round moon is seen in the sky, it is known as a full moon.
(b) New moon
Ans: When the moon is not visible in the sky, it is known as new moon.
(c) Lunar month
Ans: The period of 28 to 30 days from one new moon day to the new moon day is called a lunar month.
(d) Tithi
Ans: Every day in the lunar month is called tithi.
5. Answer the following questions.
(a) What is the equator?
Ans: An imaginary circle present between the North and the South pole is called the equator.
(b) What are the two parts of the earth made by the equator ?
Ans: The Northern hemisphere and the Southern hemisphere are the two parts of the earth made by the equator.