1. What is rotation? How much time does earth take in completing one rotation? insis
2. What is meant by the revolution of the earth?
3. What is a leap year?
What is an equinox? Which seasons areWhich seasons are indicated by it in both the hemispheres?
5. Why does the duration of day and night change in a year?
E. Answer the following questions.
1. Why are days and nights equal on 21st March at all places on the earth? Explain.
2. Explain with the help of a diagram, why seasons are reversed between Northern and Southern
Hemispheres.
3. Why does the month of February have 29 days, after every four years? Explain.
4. How do day and night occur on the earth? Explain with the help of a diagram.
Answers
Answer:
Rotation :-
the action of rotating about an axis or centre.
Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes, and 4 seconds with respect to other, distant, stars (see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past.
Revolution of earth:-
The definition of a revolution is the movement of one object around a center or another object, a forceful overthrow of a government by the people or any sudden or grand change. An example of revolution is movement of the earth around the sun.
Leap year :-
A leap year has 366 days instead of the usual 365 days, and occurs nearly every four years. The extra day during leap years is the leap day on February 29. Leap years have 366 days, not 365. We use leap years to sync our common years with the tropical years
The March equinox is the vernal equinox in the Northern Hemisphere, and the autumnal equinox in the Southern. The September equinox is the autumnal equinox in the Northern Hemisphere and the vernal in the Southern.
In the northern hemisphere: MARCH 20 (the Sun crosses the Equator moving northward). In the southern hemisphere: SEPTEMBER 22 (the Sun crosses the Equator moving southward). AUTUMN EQUINOX: The first day of the Season of Autumn - and the beginning of a long period of darkness at the Pole.
Causes of day and night :-
The change between day and night is caused by the rotation of the Earth on its axis. ... The changing lengths of days and nights depends on where you are on Earth and the time of year. Also, daylight hours are affected by the tilt of the Earth's axis and its path around the sun.
Why the seasons are reversed in the southern hemisphere ? Because of this inclination, the northern hemisphere, receives more energy from the Sun, While the southern hemisphere receives less. This corresponds to the boreal summer (in the northern hemisphere) and the southern winter (in the southern hemisphere).