State one reason why we do not feel the motions of the earth.
Answer
According to the gravitational force, everything is attached to the earth, keeping everything at rest at their original position, unless any external force compels to motivate it.
Day and night are caused by the rotation and the creation of centrifugal force resulting in a bulge in the equatorial part and flattened top at the poles.
Two characteristics of rotation are the complete rotation of the earth from west to east in 24 hours and along its tilted axis which is always in the same direction towards the Pole Star.
Twilight and Dawn depend on the path of the sun in the sky. At the Equators, the sun’s path is almost vertical. So the duration of twilight and dawn combine with sunset and sunrise.
Vertical rays are hotter, because these cross shorter distance from the sun to the earth. Consequently the tropical belt is hotter than temperate and polar areas.
25th of December in New Zealand may be one of the hottest days of the year.
Answer
The sun’s rays are vertical over the Tropic of Capricorn, So 25th December may be one of the hottest days in NewZealand, being situated in the Southern Hemisphere.
Seasons are reversed between Northern and Southern Hemisphere.
Answer
The 23.45° tilt between the equator and the orbital plane causes each Hemisphere to lean towards the sun for part of the year. So seasons are reversed between the two Hemispheres.
Altitude of the Sun varies at a place according to seasons
Answer
The altitude of the mid-day sun is related to the latitude of a place. Because of seasonal changes in the altitude of the sun at different latitudes, the altitude of midday sun also varies
This happens because tilt causes each hemisphere to lean towards the sun alternately for parts of the year. It also changes the apparent altitude of the midday Sun.
The speed of rotation at Leningrad (60°N), Genoa (45°N) and Singapore (0°N) along the Earth’s axis is not the same.
Answer
The speed of rotation at Leningrad (60°N), Genoa (45°N), and Singapore (0°N) along the Earth’s axis is not the same because of the spherical shape of the earth.
How much time does the Earth take for one revolution?
Answer
The Earth takes for one revolution around the sun 365 days 5 hours 59 minutes 16 seconds (Almost 365 days and 6 hours). The time a planet takes to revolve around the sun is called a year.
On which two days are the days and nights equal all over the world and why ? What name do you give to these days ?
Answer
On 21st March and 23rd September the days and flights are equal all over and the world due to the sun’s rays vertical on the equator. The name is Equinox of this position.
Vertical rays are hotter, because these cross shorter distance from the sun to the earth. Consequently the tropical belt is hotter than temperate and polar areas.