NCERT Solutions for Class 5 EVS Chapter 11

i. Earth-It is a planet that revolves around the sun. It is called the blue planet as three-fourth of it is covered by water and one -fourth by land. It has two Hemispheres-Northern and Southern Hemisphere.
ii. Axis- An axis is an imaginary line that runs through the earth from the North Pole to South Pole on which the earth rotates from west to east.
iii. Globe-It is the model of the earth which is a three- dimensional representation of the earth.
iv. Equator- An equator is an imaginary line around the middle of a planet or other celestial body. It is halfway between the North Pole and the South Pole, at 0 degrees’ latitude and it divides the planet into a Northern Hemisphere and a Southern Hemisphere.

Why we do not fall off the surface of the earth, even though it is round.?
Ans. We do not fall off the surface of the earth even though it is round because of the force of gravity present on the earth. Earth is like a sphere so there is no up and down. It is the force of gravity that works like a magnet which helps to pull everything towards its center. The strength of this pull depends on the mass and the distance between the objects.

Yes, moon has gravity which is one -sixth of the earth’s gravity when compared to the earth. So, any object will weigh one-sixth of its weight on the moon as compared to its weight on the earth.

No, a very small amount of gravity called Micro-gravity can be found in the space too.
It is the condition in which the people as well as the objects appear to be weightless. Its effects can be seen when the astronauts float in the space.

The ball thrown into the air comes down on the earth because the force of gravity or the earth’s gravitational field which is always focused downwards (towards the center of the earth.)
So, when the ball is thrown up, it is going against the earth’s gravitational field and so, the earth’s gravitational force pulls it back down, accelerating it downwards.

Shooting stars look like stars that shoot quickly across the sky but they are not stars in actual. They are a small piece of rock or dust that hits the earth’s atmosphere from the space. It moves too fast that it heats up and glows as it moves through the atmosphere. They are called Meteors which burnup mostly before they reach the ground. If it reaches the earth’s surface, it is called a meteoroid.

Meteor is a small body of matter which comes from the outer space and enters the earth’s atmosphere, becoming radiant due to friction and appears as a streak of light.

A meteoroid is a small rocky or metallic body found in the outer space. Meteoroids are smaller than asteroids, and range in size from small grains to one-meter-wide objects.

As there is no atmosphere on the moon, it helps to scatter the sunlight there. Since sunlight is a huge spot only, it does not have a bright glare because of which the sky appears dark at all times and thus the stars are visible during day and night.
So, if you were standing on the Moon where there is no atmosphere, you would see the stars both day and night.

The reason that we cannot see the stars and moon during the daytime is that the sun’s rays suppress the faint light coming from the stars. During the night, when the sun’s rays get blocked by the other side of the earth, it is possible to see the faint light of the stars shining in space.

The most important thing which holds to the earth because of gravity is atmosphere and water.
Without gravity the air in the atmosphere will not stick around, so it will immediately begin drifting away off into the space.
Water on the earth would also depart. And earth itself would also break into chunks and float off into space since it is held together by gravity only.

We will have to apply an effort to move up as we are going against the force of gravity, since this force works to pull everything towards the center of the earth.

When we are on the moon, we can see only half of the earth because we are able to see only that part of the earth which is receiving and reflecting the sunlight. The other part is not visible as it is not receiving the sun light.

The moon is 3,84,400 kms away from the earth.

Space craft is a machine or a vehicle that is specifically designed to be used for flying into space. It is also called a space shuttle or space ship.

The full form of NASA is National Aeronautics and Space.

We see a different phase of moon every night because the moon orbits around the earth and the part of the moon that faces the sun is lit up and the part which is not facing the sun is dark.
So, the phase of the moon depends on its position in relation to the sun and Earth. The phases change because the moon revolves around Earth and different portions of the moon’s sunlit surface are visible from Earth.

The moon is there in the sky but on a new moon night, it is directly between the earth and the sun and thus that part, which is facing us doesn’t receive sunlight and we think that the moon has disappeared.

The moon revolves around the earth in an elliptical orbit and takes 29.53 days from one full moon to another.

First Quarter is the half-moon phase that appears after the new moon and before the full moon and Last Quarter is that half-moon phase that appears before the waning crescent when it reaches the new moon phase again.

Astronomy is the study of all the things that are in the universe beyond Earth’s atmosphere which includes objects that we can see with our naked eyes, like the Sun, the Moon, the planets, and the stars. It also includes those objects that we can only see with telescopes or other instruments, like faraway galaxies and tiny particles etc.

Every night, the moon shows us a different face in the night sky. As the moon travels in its 29-day orbit, its position keeps on changing daily. Sometimes it’s between the Earth and the sun and sometimes it’s behind us. So, a different section of the moon’s face is lit up by the sun, causes it to show different phases.

Gibbous moon is the name given to the phase of the moon when the shape of the moon is between half and full moon. It is three-fourth of its size.

The Earth looks like a blue marble from the space. Some parts are brown, yellow, green and white. Water covers most of Earth.

Sunita Williams, Indian-American astronaut Sunita Williams returned to earth after 127 days in space with a new record of the most spacewalking time by a female at 50 hours and 40 minutes over seven career excursions.

A constellation is a group of stars that together form specific patterns. They are easily recognizable in the night sky and there are 88 official constellations. Few examples of a constellation are- Scorpio, Great Bear, Orion.

Asteroids are small, rocky objects that orbit the Sun. The asteroids orbit the Sun like the planets but they are much smaller than planets.

Sunita was a good friend of Kalpna Chawla who wanted to come to India and meet children of India. She came to India to fulfil Kalpana’s dream.

Sunita did not experience the pull of the earth in the space ship because the spaceship was revolving around the earth.

The shape of the earth is oblate spheroid, or oblate ellipsoid. It is an ellipsoid of revolution which is obtained by rotating an ellipse about its shorter axis. This is because the earth is flattened at the poles and bulges out at the Equator.

A natural satellite is a satellite which was created by nature, like the moon. The Earth’s moon is one example of a natural satellite.
Whereas an Artificial satellite also called man-made satellite is made by humans, like communications satellites. An artificial satellite is built on Earth and then taken into orbit by rockets or released by a space station

An eclipse occurs when an object comes in between you and another object and blocks your view. From Earth, we normally experience two kinds of eclipses: an eclipse of the Moon called the Lunar eclipse and an eclipse of the Sun called the Solar eclipse.
• A lunar eclipse is caused when the earth comes exactly between the moon and the sun and the Sun’s rays cannot hit the moon. A lunar eclipse can be seen from anywhere on the dark side of the Earth.
• A solar eclipse is caused when the moon exactly blocks the Sun’s rays from hitting the Earth. A solar eclipse can only be seen from certain places on Earth as the moon only blocks the sun for a small area. Solar Eclipses always happen during the new moon phase.