Question

What causes day and night ?

• A. the Earth revolving around the Sun
• B. the Moon blocking sunlight
• C. the Earth rotating on its axis
• D. the Earth's orbital tilt

Answer 1

Answer:

C. the Earth rotating on its axis

• Earth is spherical and it spins on its own axis. The spinning of the Earth on its own axis is called rotation. The part of the Earth facing the Sun due to rotation gets illuminated and experiences day. As the opposite face does not get sunlight, night is experienced there.

• Day and night is experienced one after the other due to the rotation of the Earth. The Earth takes 24 hours to complete one rotation. It is considered as a day.

• Sunrise and sunset: The change in the position of the Sun is experienced due to the rotation of the Earth. It is because of the rotation of the Earth from west to east that the Sun seems to rise in the east and set in the west.

• Along with the rotation on its axis, the Earth also moves around the Sun. The movement of the earth around the Sun is called revolution.

• It is due to the revolution of the Earth that we experience different seasons. It takes 365% days for the Earth to complete one revolution around the Sun, which is considered as a year.

• The speed of revolution of the Earth is 96000 km per hour.

• Day and night are caused by the rotation and seasons are caused by the revolution of the Earth.

• The Earth takes 365 days to complete one revolution. But a year normally has 365 days. The remaining ¼ part of a day will be considered as a full day once in every four years. Thus every fourth year has 366 days and is called a Leap Year.