9th Class Science Gravitation and Floatation Question Bank

done Gravitation and Pressure Total Questions - 50

• question_answer1)
  A body weighs \[72\,\,N\] on the surface of the earth. What is the gravitational force on it at a height equal to half the radius of the earth from the surface?
  A)
  \[72\,\,N\]                      done clear
  B)
  \[28\,\,N\] done clear
  C)
  \[16\,\,N\]          done clear
  D)
         \[32\,\,N\]   done clear
  View Solution play_arrow

• question_answer2)
  Where will it be profitable to purchase one kilogram sugar?
  A)
   At the poles     done clear
  B)
          At the equator done clear
  C)
   At \[{{45}^{o}}\]latitude done clear
  D)
          At \[{{40}^{o}}\]latitude done clear
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• question_answer3)
  The figure given below shows a planet in elliptical orbit around the sun\[S\]. At what position will the kinetic energy of the planet be maximum?
  A)
  \[{{P}_{1}}\]                              done clear
  B)
  \[{{P}_{4}}\] done clear
  C)
  \[{{P}_{3}}\]                done clear
  D)
         \[{{P}_{2}}\] done clear
  View Solution play_arrow

• question_answer4)
  If the mass of a body is M on the surface of the earth, what would be the mass of the same body on the surface of the moon?
  A)
  \[M/6\]   done clear
  B)
         \[Zero\] done clear
  C)
  \[M\]                   done clear
  D)
         \[2\,\,M\] done clear
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• question_answer5)
  Find the gravitational attraction between the two atoms in a hydrogen molecule when \[G\] is\[6.67\times {{10}^{-11}}N{{m}^{2}}k{{g}^{-2}}\], mass of a hydrogen atom is \[1.67\times {{10}^{-27}}kg\] and distance between the two atoms is \[1\,\overset{o}{\mathop{A}}\,\].
  A)
  \[11.14\times {{10}^{-18}}N\] done clear
  B)
  \[2.39\times {{10}^{-45}}N\] done clear
  C)
  \[1.86\times {{10}^{-44}}N\]   done clear
  D)
  \[4.18\times {{10}^{-23}}N\] done clear
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• question_answer6)
  The distances of two planets (Neptune and Saturn) from the sun are \[1013\,\,m\] and \[1012\,\,m\] respectively. Find the ratio of the time periods of the planets.
  A)
  \[100:1\]            done clear
  B)
         \[1:\sqrt{10}\] done clear
  C)
  \[\sqrt{10}:1\]    done clear
  D)
         \[10\sqrt{10}:1\]   done clear
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• question_answer7)
  When does the value of g at a place increase?
  A)
   With decrease in the latitude of the place done clear
  B)
   With increase in the latitude of the place   done clear
  C)
   With increase in the altitude of the place done clear
  D)
   With increase in the angular rotation of the earth done clear
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• question_answer8)
  Two planets \[A\] and B have their radii in the ratio of \[2:5\] and densities in the ratio of \[1:6\] respectively. Which of the following statements is NOT true regarding the given information?
  A)
   The ratio of acceleration due to gravity on them is\[1:15\]. done clear
  B)
   For the same volume of planets, mass of planet \[A\] is greater than that of planet\[B\].   done clear
  C)
   A body weighs \[15\] times more on planet \[B\] than on planet\[A\]. done clear
  D)
   Planet \[B\] has greater volume than planet\[A\]. done clear
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• question_answer9)
  Which of the following statements is NOT correct about a planet rotating around the sun in an elliptical orbit?
  A)
   Its kinetic energy is constant.   done clear
  B)
   Its angular momentum is constant. done clear
  C)
   Its areal velocity is constant. done clear
  D)
   Its time period is proportional to r3. done clear
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• question_answer10)
  Two spheres each of mass \[105\,\,kg\] and radius \[10\,\,m\] are kept in contact. Find the force of gravitation acting between them.
  A)
  \[{{10}^{-3}}N\]          done clear
  B)
         \[6.67\times {{10}^{-3}}N\]   done clear
  C)
  \[6.67\times {{10}^{-11}}N\]     done clear
  D)
         \[{{10}^{-11}}N\] done clear
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• question_answer11)
  A body weighs \[700\,\,N\] on the surface of the earth. What is its weight on the surface of a planet/whose mass is \[1/7\,\,th\] and radius is \[1/2\] as that of the earth?
  A)
  \[400\,\,N\]   done clear
  B)
         \[300\,\,N\] done clear
  C)
  \[700\,\,N\]         done clear
  D)
         \[500\,\,N\] done clear
  View Solution play_arrow

• question_answer12)
  Find the ratio of the distances travelled by a body falling freely from rest in the first, second and third seconds respectively.
  A)
  \[1:4:9\]             done clear
  B)
  \[1:2:3\] done clear
  C)
  \[1:9:25\]                       done clear
  D)
  \[1:3:5\]   done clear
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• question_answer13)
  A stone is thrown upwards with a speed \['u'\] from the top of a tower. It reaches the ground with a velocity\['3u'\]. Find the height of the tower.
  A)
  \[\sqrt{3}\]                     done clear
  B)
         \[\frac{2{{u}^{2}}}{9}\] done clear
  C)
  \[\frac{3{{u}^{2}}}{9}\]                                  done clear
  D)
  \[\frac{4{{u}^{2}}}{9}\]   done clear
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• question_answer14)
  From the top of a building of height\[40\,\,m\], a boy throws a stone vertically upwards with an initial velocity of \[10\,\,m\,\,{{s}^{-1}}\] such that it eventually falls to the ground. At what time will the stone reach the ground?\[(g=10\,\,m{{s}^{-2}})\]
  A)
  \[4s\]                   done clear
  B)
         \[3s\] done clear
  C)
  \[2s\]                             done clear
  D)
  \[1s\] done clear
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• question_answer15)
  Points \[P,\,\,Q\] and \[R\] are in a vertical line such that\[PQ=QR\]. A ball at the top-most point \['P'\] is allowed to fall freely. What is the ratio of the times of descent through \[PQ\] and\[PR\]?
  A)
  \[\frac{3}{2}\]               done clear
  B)
         \[\frac{3}{\sqrt{2}+1}\] done clear
  C)
  \[\frac{1}{\sqrt{2}-1}\]     done clear
  D)
         \[\frac{5}{2}\] done clear
  View Solution play_arrow

• question_answer16)
  If it is safe to jump from a height of \[2\,\,m\] on to the earth, what would be the safe height on a planet where the value of \['g'\] is\[1.96\,\,m\,\,{{s}^{-2}}\]?
  A)
  \[2m\]                            done clear
  B)
  \[4m\] done clear
  C)
  \[6m\]                done clear
  D)
         \[10m\]   done clear
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• question_answer17)
  A wooden block of mass \[10\,\,g\] is dropped on the top of a cliff \[100\,\,m\] high. Simultaneously, a bullet of mass \[10\,\,g\] is fired from the foot of the cliff upward with a velocity of\[100\,\,m\,\,{{s}^{-1}}\]. At what time will the bullet and the wooden block meet?\[(g=32\,\,ft\,\,{{s}^{-2}})\]
  A)
  \[1s\]                   done clear
  B)
         \[2s\] done clear
  C)
  \[3s\]                 done clear
  D)
         \[4s\] done clear
  View Solution play_arrow

• question_answer18)
  A body is projected vertically upwards with a velocity of\[96\,\,ft\,\,{{s}^{-1}}\]. How long will the body remain in air?\[(g=32\,\,ft\,{{s}^{-2}})\]
  A)
  \[3s\]                 done clear
  B)
         \[6s\]   done clear
  C)
  \[9s\]                 done clear
  D)
         \[12s\] done clear
  View Solution play_arrow

• question_answer19)
  A body falling freely from rest covers \[\frac{7}{16}\] of the total height in the last second of its fall. What is the height from which it falls?
  A)
  \[24.2\,\,m\]       done clear
  B)
         \[38.4\,\,m\] done clear
  C)
  \[78.4\,\,m\]         done clear
  D)
         \[46.8\,\,m\] done clear
  View Solution play_arrow

• question_answer20)
  If a freely falling body travels in the last second a distance equal to the distance travelled by it in the first \[3\] seconds. Find the time of its travel.
  A)
  \[3s\]                 done clear
  B)
         \[4s\] done clear
  C)
  \[5s\]                               done clear
  D)
  \[6s\] done clear
  View Solution play_arrow

• question_answer21)
  Two stones are thrown from the top of a building with the same speed\[u\], one in the upward direction and the other in the downward direction. When they reach the ground/they acquire certain velocities \[{{v}_{1}}\] and \[{{v}_{2}}\] respectively. What is the ratio of \[{{v}_{1}}\] and\[{{v}_{2}}\]?
  A)
  \[1:1\]                  done clear
  B)
         \[1:2\] done clear
  C)
  \[2:1\]                done clear
  D)
         \[2:3\] done clear
  View Solution play_arrow

• question_answer22)
  A freely falling body covers half of its journey from the top of a tower in\[0.5\,\,s\]. What is the height of the tower?
  A)
  \[4.9\,\,m\]         done clear
  B)
         \[2.45\,\,m\]   done clear
  C)
  \[9.8\,\,m\]         done clear
  D)
         \[9\,\,m\] done clear
  View Solution play_arrow

• question_answer23)
  A stone is dropped from a tower. It was found that it covered a distance of \[45\,\,m\] during its last second of the fall. Calculate the time of the fall and the height of the tower?\[(g=10\,\,m\,\,{{s}^{-2}})\]
  A)
  \[5s,\,\,45m\]      done clear
  B)
         \[10s,\,\,90m\] done clear
  C)
  \[5s,\,\,125m\]      done clear
  D)
         \[10s,\,\,100m\] done clear
  View Solution play_arrow

• question_answer24)
  As we go from the equator towards the poles/the value of\[g\]
  A)
   remains the same. done clear
  B)
   decreases. done clear
  C)
   increases.   done clear
  D)
   decreases up to the altitude of \[{{45}^{o}}\] and then increases done clear
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• question_answer25)
  To reach the same height on the moon as on the earth, a body must be projected up with
  A)
   higher velocity on the moon. done clear
  B)
   lower velocity on the moon.   done clear
  C)
   same velocity on the moon as that of the earth. done clear
  D)
   It depends on the mass of the body. done clear
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• question_answer26)
  A diver is \[20\,\,m\] below the water surface. Given that the density of the water is\[1000\,\,kg\,\,{{m}^{-3}}\], what is the pressure exerted by the water on the diver? (Take\[g=10\,\,m{{s}^{-2}}\])
  A)
  \[10,000Pa\]       done clear
  B)
         \[1,00,000Pa\] done clear
  C)
  \[2,00,000Pa\]      done clear
  D)
         \[3,00,000Pa\] done clear
  View Solution play_arrow

• question_answer27)
  A liquid exerts a pressure of \[100,999\,\,Pa\] on an object when it is \[73.5\,\,cm\] below the liquid surface. What is the density of the liquid? (Take\[g=10\,\,m{{s}^{-2}}\])
  A)
  \[136\,\,kg\,\,{{m}^{-3}}\]                     done clear
  B)
  \[272\,\,kg\,\,{{m}^{-3}}\] done clear
  C)
  \[13,700\,\,kg\,\,{{m}^{-3}}\]   done clear
  D)
  \[27,200\,\,kg\,\,{{m}^{-3}}\] done clear
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• question_answer28)
  The diagram given below shows a special flask filled with water. Which of the following statements is true?
  A)
   Point \[P\] has a higher pressure than point\[Q\]. done clear
  B)
   Point \[R\] has a higher pressure than point\[Q\]. done clear
  C)
   Point \[Q\] has the highest pressure as compared to point \[P\] and point\[R\]. done clear
  D)
   Point\[P\], point \[Q\] and point \[R\] have the same pressure.   done clear
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• question_answer29)
  A hollow metal sphere of mass \[180.6\,\,g\] contains a cavity of volume\[2.5\,\,c{{m}^{3}}\]. This metal when placed in water/displaces \[24\,\,cc\] of water. Find the specific gravity of the metal.
  A)
  \[21.5\,\,g\,c{{m}^{-3}}\]          done clear
  B)
         \[6.3\,\,g\,\,c{{m}^{-3}}\] done clear
  C)
  \[8.4\,\,g\,\,c{{m}^{-3}}\]           done clear
  D)
         \[24\,\,g\,\,c{{m}^{-3}}\] done clear
  View Solution play_arrow

• question_answer30)
  A rectangular tank of \[6\,\,m\] long, \[2\,\,m\] broad and \[2\,\,m\] deep is full of water, what is the thrust acting on the bottom of the tank?
  A)
  \[23.52\times {{10}^{4}}N\]   done clear
  B)
  \[23.52N\] done clear
  C)
  \[11.76\times {{10}^{4}}N\]                  done clear
  D)
  \[3.92\times {{10}^{4}}N\] done clear
  View Solution play_arrow

• question_answer31)
  When a body is immersed in a liquid/what is the loss in its weight equal to?
  A)
   The weight of the liquid done clear
  B)
   The weight of the body done clear
  C)
   The difference in the weights of body in air and in liquid done clear
  D)
   The upthrust of liquid on the body   done clear
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• question_answer32)
  A body of density \[\rho \] and volume \[V\] is floating in a liquid of density\[\sigma \], then which of the following statements about the body is correct?
  A)
   Its true weight is\[V\sigma g\]. done clear
  B)
   Loss in its weight is\[V\sigma g\]. done clear
  C)
   Its apparent weight is zero.   done clear
  D)
   Its density \[\rho \] is greater than that of liquid\[\sigma \]. done clear
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• question_answer33)
  Equal masses of water and a liquid of relative density \[2\] are mixed together/then what is the density of the mixture (in\[g\,\,c{{m}^{-3}}\])?
  A)
  \[2/3\]                done clear
  B)
         \[4/3\]   done clear
  C)
  \[3/2\]                done clear
  D)
         \[3\] done clear
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• question_answer34)
  Which of the following is NOT a factor on which pressure at a point inside a liquid depends?
  A)
   The depth of the point below the surface of the liquid done clear
  B)
   The nature of the liquid done clear
  C)
   The acceleration due to gravity at that point done clear
  D)
   The shape of the containing vessel   done clear
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• question_answer35)
  Two stretched membranes of area \[2\,\,c{{m}^{2}}\] and \[3\,\,c{{m}^{2}}\] are placed in a liquid at the same depth. Find the ratio of the pressure on them.
  A)
  \[1:1\]                  done clear
  B)
         \[2:3\] done clear
  C)
  \[3:2\]                done clear
  D)
         \[{{2}^{2}}:{{3}^{2}}\] done clear
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• question_answer36)
  If a body floats with \[{{\left( \frac{p}{q} \right)}^{th}}\] of its volume above the surface of water, find the relative density of the body.
  A)
  \[\frac{q+p}{q}\]           done clear
  B)
         \[1-\frac{p}{q}\]   done clear
  C)
  \[\frac{1-p}{q}\] done clear
  D)
         \[\frac{p}{q}\] done clear
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• question_answer37)
  A rectangular iron block is placed over a table in different ways such that different faces touch the table. In all these cases, which of the following can be concluded?
  A)
   The block exerts the same thrust and same pressures. done clear
  B)
   The block exerts the same thrust and different pressure.   done clear
  C)
   The block exerts different thrusts but the same pressures. done clear
  D)
   The block exerts different thrusts and different pressures. done clear
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• question_answer38)
  A stone is thrown vertically upwards with an initial velocity of\[14\,\,m\,\,{{s}^{-1}}\]. Find the time taken by the stone to strike the ground. (Take\[g=9.8\,\,m\,\,{{s}^{-2}}\])
  A)
  \[2.86\,\,s\]                       done clear
  B)
  \[3.46\,\,s\] done clear
  C)
  \[3.86\,\,s\]         done clear
  D)
         \[4.86\,\,s\] done clear
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• question_answer39)
  Choose the correct statement among the following.
  A)
   The upper surface of a stationary liquid is always horizontal. done clear
  B)
   The pressure of a given liquid is directly proportional to the depth of the liquid. done clear
  C)
   Pressure at a given depth inside a stationary liquid is different at all points on the horizontal plane. done clear
  D)
   Both [a] and [b]   done clear
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• question_answer40)
  Compare the pressure exerted by a sharp needle on a surface and the pressure exerted by a blunt needle.
  A)
   The pressure exerted by a sharp needle is more.   done clear
  B)
   The pressure exerted by a blunt needle is less. done clear
  C)
   The pressure exerted by both is equal. done clear
  D)
   It cannot be determined. done clear
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• question_answer41)
  If suddenly the gravitational force of attraction between the earth and a satellite revolving around it becomes zero, what will happen?
  A)
   The satellite will continue to move in its orbit with the same velocity. done clear
  B)
   The satellite will move tangentially and escape away from its orbit.   done clear
  C)
   The satellite will become stationary in its orbit. done clear
  D)
   The satellite will move towards the earth. done clear
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• question_answer42)
  Which of the following statements regarding gravitational force existing between two bodies is true?
  A)
   The first body exerts attractive force on the second body while the second body exerts repulsive force on the first body. done clear
  B)
   The gravitational force is zero when they are kept in vacuum. done clear
  C)
   Force exerted by the first body on the second is not equal to the force exerted by the second body on the first. done clear
  D)
   Force exerted by the first body on the second body is equal to the force exerted by the second body on the first.   done clear
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• question_answer43)
  A wooden cylinder floats vertically in water with one fourth of its length immersed. What will be the density of wood?
  A)
   It equals to the density of water. done clear
  B)
   It equals to half the density of water. done clear
  C)
   It equals to one fourth the density of water.   done clear
  D)
   It equals to three fourths the density of water. done clear
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• question_answer44)
  A body weighs \[12\,\,N\] on the surface of the moon. What is its weight on the surface of the earth?
  A)
  \[72\,\,N\]            done clear
  B)
         \[2\,\,N\] done clear
  C)
  \[24\,\,N\]          done clear
  D)
         \[Zero\] done clear
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• question_answer45)
  If \[F\]is the force between two bodies of masses \[{{m}_{1}}\] and \[{{m}_{2}}\] at certain separation, then what is the force between \[\sqrt{5}{{m}_{1}}\]and \[\sqrt{3}{{m}_{2}}\] at the same separation?
  A)
  \[\sqrt{5}F\]                   done clear
  B)
         \[F/\sqrt{15}\] done clear
  C)
  \[\sqrt{15}F\]                   done clear
  D)
  \[F\] done clear
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• question_answer46)
  A stone is dropped from a building and \[2\] seconds later another stone is dropped. How far apart are these two stones by the time the first one reaches a speed of\[30\,\,m\,\,{{s}^{-1}}\](Take\[g=10\,\,m\,\,{{s}^{-2}}\])
  A)
  \[80\,\,m\]                      done clear
  B)
  \[100\,\,m\] done clear
  C)
  \[60\,\,m\]          done clear
  D)
         \[40\,\,m\]   done clear
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• question_answer47)
  Analyse the given statements and choose the correct option. Statement I: The buoyant force of water on a submerged wooden cube is greater than the buoyant force of water on a steel cube of equal volume. Statement II: The buoyant force on a body is equal to the weight of the liquid displaced by the body.
  A)
   Both statement I and statement II are correct and statement II is the correct explanation of statement I. done clear
  B)
   Both statement I and statement II are correct, but statement II is not the correct explanation of statement I. done clear
  C)
   Statement I is correct, but statement II is incorrect. done clear
  D)
  (d Statement I is incorrect, but statement II is correct.   done clear
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• question_answer48)
  A block of wood of length \[40\,\,cm\] and area of cross section \[15\,\,c{{m}^{2}}\] floats in water with \[3/8\] of its length above water. What is the density of wood? (density of wafer \[=1\,\,g\,\,c{{m}^{-3}}\])
  A)
  \[0.256\,\,g\,\,c{{m}^{-3}}\]                  done clear
  B)
  \[0.526\,\,g\,\,c{{m}^{-3}}\] done clear
  C)
  \[0.625\,\,g\,\,c{{m}^{-3}}\]        done clear
  D)
         \[0.650\,\,g\,\,c{{m}^{-3}}\] done clear
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• question_answer49)
  Two bodies of masses \[20\,\,kg\] and \[15\,\,kg\] are dropped from the top of a building. At any instant during the fall, which of the following energies will both the bodies possess in equal measure?
  A)
   Potential energy done clear
  B)
   Kinetic energy done clear
  C)
   Momentum done clear
  D)
   Acceleration   done clear
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• question_answer50)
  A ball is released from the top of a tower of height \['h'\] metres. It takes \[T\] seconds to reach the ground. What is the position of the ball in \[T/3\] seconds?
  A)
  \[h/9\] metres from the ground done clear
  B)
   \[7h/9\,\,m\] m from the ground done clear
  C)
   \[8h/9\] metres from the ground   done clear
  D)
   \[17h/18\,\,m\] from the ground done clear
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