Tag: our earth and our solar system

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Questions Related to our earth and our solar system

Multiple choice evs - ii our earth and our solar system solar system and sun planets and stars introduction to solar system planets sunita's experience in space space exploration

The globe of Saturn can contain about

  1. 150 Earths

  2. 472Earths

  3. 355 Earths

  4. 729 Earths
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Radius of Saturn is about $9$ times than that of earth.

Let, n number of earths a saturn contains. So equating volume.
$n{ V } _{ earth }={ V } _{ saturn }\ n\times \cfrac { 4 }{ 3 } \pi { r }^{ 3 }=\cfrac { 4 }{ 3 } \pi { (9{ r }) }^{ 3 }\ n={ 9 }^{ 3 }\ n=729$

Multiple choice evs - ii our earth and our solar system solar system and sun planets and stars introduction to solar system planets sunita's experience in space space exploration

Reflection of the sunlight from the upper layers of the Earth's atmosphere causes

  1. days and nights

  2. tides

  3. eclipses

  4. twilight
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Twilight is seen because the earth's atmosphere, some light scatters through small particles in the atmosphere- so, there is still some light n the sky even after the sun  has gone down.


Multiple choice evs - ii our earth and our solar system solar system and sun planets and stars introduction to solar system planets sunita's experience in space space exploration

Venus appears very bright because it reflects about ....... percent of the light which it receives from the Sun.

  1. 50

  2. 60

  3. 75

  4. 100
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

First of all venus is very close to earth so very less amount of light gets scattered by atmosphere particles and second thing is it reflects $75\%$ of the light coming from sun.

Multiple choice evs - ii our earth and our solar system solar system and sun planets and stars introduction to solar system planets sunita's experience in space space exploration

Surface gravity of different planets in correct decreasing order is

  1. Neptune, Jupiter, Saturn, Earth

  2. Jupiter, Neptune, Earth, Saturn

  3. Jupiter, Neptune, Saturn, Earth

  4. Jupiter, Uranus, Neptune, Saturn
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Surface gravity of different planets has a unique surface gravity.
Newton's second law of motion: $F=ma$............(1)
Law of universal gravitation: $F _g=\dfrac{GM _1M _2}{R^2}$............(2)
The value of $G$ was originally determined experimentally by Henry Cavendish and has a value of $6.67\times10^{11} N m^3/kgs^{2}$
By using these two equations, one can derive another equation that shows the acceleration due to gravity at the surface of a planet, i.e., $g=\dfrac{GM}{R^2}$
Where $M$ is the mass of the planet and $R$ is its radius.
The surface gravity of the planets, as determined by the equation above and shown relative to Earth's gravity can be seen below:

Object:           g/g-earth:       Acceleration at the surface

Earth...............$1.0$...............$g = 9.78\ m/s^2$ ($32.1\ ft/s^2$)

Jupiter.............$2.36$...........$g = 23.1\ m/s^2$ ($75.9\ ft/s^2$)

Saturn.............$1.07$.............$g = 9.05\ m/s^2$($29.4\ ft/s^2$)

Uranus............$0.889$...........$g = 8.69\ m/s^2$($28.5\ ft/s^2$)

Neptune..........$1.12$.............$g = 11.0\ m/s^2$($36.0\ ft/s^2$)

So, surface gravity of different planets in correct decreasing order is Jupiter, Neptune, Saturn, Earth.