SSC Worksheet for Chapter -1 Stars and Our Solar System Class 8

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Find SSC Worksheet for chapter-1 Stars and Our Solar System class 8

CLASS-8

BOARD: SSC

Physics Worksheet -1

TOPIC: Stars and Our Solar System

For other SCC Worksheet for class 8 Science check out main page of Physics Wallah.

Fill in the blanks :

1. The time period of rotation of moon about its axis is _________ as compared to time period of revolution of moon around the earth.

2. Direction of rotation of earth about its axis is from _________ to _________ .

3. _________ is often referred to as a falling star.

4. Comets revolve around sun in _________ orbits.

5. Heavenly bodies revolving in the gap between Mar and Jupiter are called _________ .

6. _________ is a planet whose density is less than water.

7. _________ are called inferior planets.

8. _________ is called Red plant.

9. Write a note on constellations.

10. Write a note on artificial satellites of the Earth.

11. Describe the various uses of artificial satellites.

12. Why do we see only one side of the moon?

13. Why do planets not collide into one another?

14. State some special characteristics of the following planets.

(a) Mercury

(b) Venus

(c) Earth

(d) Mars

(e) Jupiter

(f) Saturn

Solutions: to worksheet-1 Topic- Stars and Our Solar System

1. Equal

2. West, East

3. Meteor

4. Elliptical

5. Asteroids

6. Saturn

7. Mercury and Venus

8. Mars

9. The stars forming a group that has a recognisable shape is called a constellation.

Constellations were devised by ancient people to be able to recognize stars in the sky.

The shapes of constellations resemble objects familiar to those people.

Some of the important constellations are:

1.Orion(or Hunter) ‘Vyadha or Mirga’

2.Ursa major(or Great bear) ‘Saptarishi’

3.Ursa minor(or little bear) ‘laghu saptarishi’

4.Pleides‘Kruttika’

5.Scorpio‘Vrichchika’

6.Cassiopeia‘Sarmishtka’

10. A satellite is any object or body that orbits around another object. An artificial satellite is any human made object designed to orbit the Earth or any other celestial body. India has built and launched several artificial satellites. Aryabhatta was the first Indian satellite. Some other Indian satellites are INSAT, IRS, Kalpana-1, EDUSAT, etc

11. Artificial satellites have many practical applications. They are used for forecasting weather, transmitting television and radio signals. They are also used for telecommunication and remote sensing.

12. The Moon makes one rotation, relative to Earth, every 29.5 days. That happens to also be the time it takes for the Moon to complete one revolution around the Earth. In the past, the Moon rotated much faster, but, over millions of years, the effect of the Earth’s gravity has slowed the Moon’s rotation until it became gravitationally locked to the Earth. So, we always see the same side of the Moon.

13. Every planet has different size and is placed at different distance from the sun. The gravitational pull between the sun and the planet depends upon the distance and size of the planet and hence affects the speed of rotation and revolution of the planet around its own axes as well as around the sun. This specific distance and speed of revolution and rotation locks the planet in its orbit having specific radius which is unique for every planet. This is the reason they have separate path and speed to rotate around its own axes as well as around the sun, hence they do not collide with each other.

14.

(a) Mercury:

(i) Closest to the sun.
(ii) Very small compared to its neighbours
(iii) It has the smallest axial tilt

(b) Venus:
(i) Hottest planet in the solar system
(ii) Very thick atmosphere consisting almost entirely of carbon dioxide
(iii) Brightest object in the sky other than the sun and moon

(c) Earth:
(i) only planet that we know for sure that harbors life.
(ii) Only planet that we know for sure that has liquid water.

(iii) Has the largest natural satellite compared to its size.
(d) Mars:
(i) Approximately the same size as the Earth
(ii) Red in visual appearance due to various oxides of iron on the first few inches of the crust.
(iii) Has the largest volcano in our solar system. Olympus Mons 24 km high and 550 km across
(e) Jupiter:
(i) Largest planet in our solar system
(ii) It’s two closest natural satellites, Io and Europa have complete opposite characteristics. Io is a land of massive volcanism while Europa is a land of Ice and water.
(iii) The Great Red Spot. A high pressure storm that has been active for at least 400 years.
(f) Saturn:

(i) Has the most visible ring system
(ii) It could actually float on water due to it's extremely low density.

(iii) It generates a tremendous amount of heat on its own