3. Motions of the Earth
EXERCISE I
A. Answer the following questions in brief:
1.
What is rotation of Earth?
2.
What is meant by "Inclination of the Earth's axis"?
3.
What causes the cycles of season?
4.
Where do the vertical rays of the sun fall on June 21?
5.
On September 23rd, which season is experienced in the Northern Hemisphere?
6.
When is the Winter Solstice?
7.
On September 23`d, which season is experienced in the Southern Hemisphere?
B. Distinguish between the following:
1.
Summer Solstice and Winter Solstice
2.
Spring Equinox and Autumn Equinox
3.
Rotation and Revolvation
C. Give Reasons:
1.
The sun rises in the east and sets in the west.
2.
Days and Nights are not always equal.
3.
On June 21", the South Pole is in continuous darkness.
4.
Why do the sun, the moon and the stars appear moving round the earth, from east
to west?
D. Fill in the blanks:
1.
The Earth rotates from to
2.
The is the line around which the earth turns.
3.
The path along which Earth travels around the sun is called the
4.
The areas experience six months long
day and six months long night.
Activities:
1.
Put a vertical stick on the ground and watch its shadow. When the shadow is the
shortest, it is 12 noon (local time). Adjust your watch to this time and find
out the difference between the local time of your town and the Indian Standard
Time.
2.
Collect information from the newspapers about the time of sunrise and sunset at
various places in the country. Calculate the time difference in the sunrise at
your town and eastern most and western most places in India.
3. Make a chart of the length of the day at
your town on the first of every month. In which month are the days the longest
and why?
4.
A quiz contest be held in class on 'Motions of Earth'.
