Rimi Ghosh

Shreya Saha

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Rimi Ghosh

Shreya Saha

ROTATION OF THE EARTH: ITS DIRECTION

Rimi Ghosh

Shreya Saha

ROTATION OF THE EARTH: ITS SPEED•The earth rotates once every 23 hours, 56 minutes and 4.09053 seconds,

called the sidereal period, and its circumference is roughly 40,075

kilometers.

•Thus, the surface of the earth at the equator moves at a speed of 460 meters

per second--or roughly 1,000 miles per hour.

Rimi Ghosh

Shreya Saha

ROTATION OF THE EARTH: DAY AND NIGHT OCCURANCE

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Rimi Ghosh

Shreya Saha

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Rimi Ghosh

Shreya Saha

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Rimi Ghosh

Shreya Saha

Rimi Ghosh

Shreya Saha

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Rimi Ghosh

Shreya Saha

1. How do you describe the rotation of the Earth?

Ans: Earth's Rotation. The earth rotates about an imaginary line that passes through the North and South

Poles of the planet. This line is called the axis of rotation. Earth rotates about this axis once each day

(approximately 24 hours).

2. What does the rotation of the Earth cause?

Ans: As Earth rotates, the Moon's gravity causes the oceans to seem to rise and fall. (The Sun

also does this, but not as much.) There is a little bit of friction between the tides and the

turning Earth, causing the rotation to slow down just a little.

3. What is the motion of Earth?

Ans: Rotation and Revolution are two motions of the earth. When earth spins or rotates around its axis,

that movement of spinning is called Rotation of Earth. And when earth spins or revolves around the sun,

that movement is called Revolution of Earth.

4. What is Earth made of?

Ans: The Earth is made out of many things. Deep inside Earth, near its center, lies Earth's core which is

mostly made up of nickel and iron. Above the core is Earth's mantle, which is made up of rock containing silicon, iron,

magnesium, aluminum, oxygen and other minerals.

Rimi Ghosh

Shreya Saha

5. Why don't we feel Earth move?

Ans: Earth moves very fast. It spins (rotates) at a speed of about 1,000 miles (1600 kilometers) per hour and

orbits around the Sun at a speed of about 67,000 miles (107,000 kilometers) per hour. We do not feel any of

this motion because these speeds are constant.

6. Why is Earth’s rotation important?

Ans: As Earth rotates, the Moon's gravity causes the oceans to seem to rise and fall. (The Sun also does this,

but not as much.) There is a little bit of friction between the tides and the turning Earth, causing

the rotation to slow down just a little. As Earth slows, it lets the Moon creep away.

7. What would happen if Earth stopped spinning for 42seconds?

Ans: Assuming that the earth stops suddenly for 42 seconds and then starts spinning again at its normal

speed, here's what would happen: 1. If the earth stops spinning suddenly, the atmosphere will continue to

spin. This means very high speed winds, i.e., approximately 1,670 Km/hr which is earth's rotational velocity.

8. Will the Earth stop rotating?

Ans: The Earth will never stop rotating. Earth rotates in the purest, most perfect vacuum in the whole

universe—empty space. Space is so empty, so devoid of anything to slow the Earth down, that it just spins

and spins, practically without friction.

❑ Go through the answers very well and get prepared for the next on line class.

Rimi Ghosh

Shreya Saha