Tag: universe and space science

Questions Related to universe and space science

Blow a balloon and let it go. You will find it moving in the direction opposite to the direction in which the air is ejected. This demonstrates :

physics satellite launch vehicles rocket propellants universe and space science xx radio telescope and space telescopes launching vehicles

  1. the principle of rocket propulsion

  2. the principle of combustion

  3. the principle of conservation of energy

  4. None of the above

Show answer
Correct Option: A
Explanation:

The principle of rocket propulsion works on the 'Newton's Third Law of Motion'. It states that, 'to every action, there is always an equal and opposite reaction'.

In the case of a rocket, the engine emits hot burning gases in the downward direction. These gases apply an equal and opposite reaction force to the rocket in the upward direction.
This is how a rocket is propelled.
Rocket propulsion is similar to the example of the situation in which, if we blow a balloon and let it go, it starts moving in the direction opposite to the direction in which the air is ejected. 
Balloon forces out the air inside it. The air applies an equal and opposite reaction force to the balloon.

The scientific instrument which is usually placed in the front region of the rocket is called :

physics satellite launch vehicles rocket propellants universe and space science xx radio telescope and space telescopes launching vehicles

  1. PAYBOOK

  2. PLAYOAD

  3. PAYLOAD

  4. PLAYWOOD

Show answer
Correct Option: C
Explanation:

The scientific instrument placed in the front region of the rocket is called PAYLOAD. For a rocket payload can be a satellite, space probe or a space craft carrying humans. The fraction of payload to the total liftoff weight of the rocket iscalled as palyload friction.

The principle of rocket propulsion depends on :

physics satellite launch vehicles rocket propellants universe and space science xx radio telescope and space telescopes launching vehicles

  1. Newton's third law of motion

  2. Principle of conservation of momentum

  3. Either A and B

  4. Both A and B

Show answer
Correct Option: D
Explanation:

The principle of rocket propulsion works on the 'Newton's Third Law of Motion'. It states that, 'to every action, there is always an equal and opposite reaction'.

In the case of a rocket, the engine emits hot burning gases in the downward direction. These gases apply an equal and opposite reaction force to the rocket in the upward direction.
This is how a rocket is propelled.
The principle of conservation of momentum states that whenever two bodies collide or get separated, then their  total momentum before collision or separation is equal to their total momentum after collision or separation.
Since the gases of the rocket and the rocket are stationery at the start, their total momentum is zero. After the gases start burning, the momentum imparted to the rocket is equal and opposite to that of the gases. Hence their total momentum is zero.

Communication satellites move in orbits of radius 44,400 km around the earth find the acceleration of such a satelite, assuming that the only force acting on, it is that  due to the earth.Mass of the earth $ = 6 \times {10^{24}}Kg.$

physics universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. $0.2\;m{s^{ - 2}}$

  2. $2.1\;m{s^{ - 2}}$

  3. $4.2\;m{s^{ - 2}}$

  4. $0.3\;m{s^{ - 2}}$

Show answer
Correct Option: A

A particle is projected vertically upward and is at a height h after $\displaystyle { t } _{ 1 }$ seconds and again after $\displaystyle { t } _{ 2 }$ seconds, then:

physics universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. $\displaystyle h={ gt } _{ 1 }{ t } _{ 2 }$

  2. $\displaystyle h=\frac { 1 }{ 2 } { gt } _{ 1 }{ t } _{ 2 }$

  3. $\displaystyle h=\frac { 2 }{ g } { t } _{ 1 }{ t } _{ 2 }$

  4. $\displaystyle h=\sqrt { { gt } _{ 1 }{ t } _{ 2 } } $

Show answer
Correct Option: B
Explanation:

Let u be the velocity of the projection and O be the point of projection. Let P be the point in the path of the particle such that OP=h. Then,
$\displaystyle h=ut-\frac { 1 }{ 2 } { gt }^{ 2 }\Rightarrow { gt }^{ 2 }-2ut+2h=0$...(i)
Clearly, $\displaystyle { t } _{ 1 }{ t } _{ 2 }$, are two roots of this equation.
$\displaystyle \therefore \quad { t } _{ 1 }{ t } _{ 2 }=\frac { 2h }{ g } $
$\displaystyle \Rightarrow \quad h=\frac { 1 }{ 2 } g{ t } _{ 1 }{ t } _{ 2 }$

In case of an orbiting satellite, if the radius of orbit is decreased.

physics universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. Its KE decreases

  2. Its PE decreases

  3. Its ME decreases

  4. Its speed decreases

Show answer
Correct Option: B,C
Explanation:

P.E of orbiting satellite at distance $r$ from centre of earth

$=\cfrac{-GMm}{r}\\K.E=\cfrac{GMm}{2R}$ and $M.E=\cfrac{-GMm}{2R}$

If $R$ decreased K.E increases.

P.E and M.E become more negative, thus decrease.

If for a given angle of projection, the horizontal range is doubled, the time of flight becomes

physics universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. $4 times$

  2. $2 times$

  3. $\sqrt 2 \;times$

  4. $\frac{1}{{\sqrt 2 }}\;times$

Show answer
Correct Option: C
Explanation:
$r=\dfrac { { u }^{ 2 }\sin2\theta  }{ g } $
Hence $R=2r=\dfrac { { V }^{ 2 }2\sin2\theta  }{ g } $
${ u }^{ 2 }=\dfrac { { V }^{ 2 } }{ 2 } \Rightarrow V=\left[ { \left( 2 \right)  }^{ 1/2 } \right] 4$
$t=\dfrac { 2u\sin\theta  }{ g } $
$T=\dfrac { 2V\sin\theta  }{ g } $
    $=\dfrac { 2\times { 2 }^{ 1/2 }\times u\sin\theta  }{ g } $
    $=\left( { 2 }^{ 1/2 } \right) t$
    $={ \left( 2 \right)  }^{ 1/2 }$
    $=\sqrt { 2 } $ times

Two identical satellites are moving in the same circular orbit around the earth but in opposite senses of rotation, Assuming an inelastic collision to take place, so that the wreckage remains as one piece of tangled material  wreckage

physics universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. will be moving in a circular orbit of half the radius

  2. will be moving in a circular orbit on one fourth the radius

  3. will spin with no translatory motion

  4. falls directly down

Show answer
Correct Option: C
Explanation:

The wreckage will spin with no translatory motion$.$

Hence,
option $(C)$ is correct answer.  

The full form of NASA is ?

evs - i universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. National Aerospace and Space Administration

  2. National Aeronautics and Satellite Administration

  3. National Aeronautics and Space Administration

  4. National Aeronautics and Space Academy

Show answer
Correct Option: C
Explanation:

The National Aeronautics and Space Administration (NASA) is an independent agency of the US federal govt. responsible for the civilian space program and aeronautics and aerospace research.

State whether the given statement is True or False :

The space shuttle is moving van which carries astronauts and many things in space ?

evs - i universe and space science launching of an artificial satellites around the earth launching of satellite india’s space programmes

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

The given statement is true. Space shuttle carries satellites to space for research work. Along with research, space shuttle is also used to carry astronauts on various heavenly bodies for research work.