Practice Test 3

Choose the best answer

  1. Convert 3.2 radians to degrees.
    1. 344.402 deg
    2. 264.523 deg
    3. 63.957 deg
    4. 204.059 deg
    5. 183.346 deg
    Answer: E

  2. An object is revolving in a circular path of radius 2 m
    with a uniform speed of 21 m ⁄ s. How many
    cycles does it execute per second.
    1. 1.671 Hz
    2. 1.271 Hz
    3. 0.354 Hz
    4. 2.507 Hz
    5. 2.75 Hz
    Answer: A

  3. An object is revolving in a circular path of
    radius 6 m with a uniform speed. If it makes
    5 revolutions in 21 seconds, calculate
    its speed.
    1. 1.401 m ⁄ s
    2. 3.306 m ⁄ s
    3. 8.976 m ⁄ s
    4. 15.162 m ⁄ s
    5. 6.737 m ⁄ s
    Answer: C

  4. An object is revolving in a circular path of
    radius 6 m with a uniform speed. If it makes
    19 cycles per second, calculate its
    centripetal acceleration.
    1. 72837.281 m ⁄ s 2
    2. 21929.293 m ⁄ s 2
    3. 141085.242 m ⁄ s 2
    4. 85510.253 m ⁄ s 2
    5. 119937.125 m ⁄ s 2
    Answer: D

  5. Centrpetal acceleration of a circular motion
    1. is acceleration due to change in angular speed
    2. is acceleration due to the change in direction
      of the velocity.
    3. is the same with angular acceleration
    4. is acceleration due to change of speed and
      change in the direction of the velocity
    5. is acceleration due to change of speed
    Answer: B

  6. An object is revolving in a circular path of radius 4 m
    with a uniform speed of 16 m ⁄ s. Calculate its
    angular velocity.
    1. 5.487 rad ⁄ s
    2. 4 rad ⁄ s
    3. 2.732 rad ⁄ s
    4. 6.079 rad ⁄ s
    5. 1.905 rad ⁄ s
    Answer: B

  7. An object is revolving in a circular path of
    radius 4.2 m with an angular acceleration of 6 rad ⁄ s 2.
    At a time when its angular speed is 15 rad ⁄ s, calculate the net
    acceleration of the object.
    1. 1736.353 m ⁄ s 2
    2. 519.137 m ⁄ s 2
    3. 945.336 m ⁄ s 2
    4. 342.173 m ⁄ s 2
    5. 759.562 m ⁄ s 2
    Answer: C

  8. Gravitational force between two objects is
    1. an attractive force which is proportional to the
      product of the masses of the objects and
      inversely proportional to the square of the
      distance separating the two objects.
    2. a repulsive force which is proportional to the
      product of the masses of the objects and
      inversely proportional to the distance
      separating the two objects.
    3. an attractive force which is proportional to the
      product of the masses of the objects and
      inversely proportional to the distance
      separating the two objects.
    4. an attractive force which is proportional to the
      sum of the masses of the objects and
      inversely proportional to the distance
      separating the two objects.
    5. an attractive force which is proportional to the
      sum of the masses of the objects and
      inversely proportional to the square of the
      distance separating the two objects.
    Answer: A

  9. A satelite of mass 700000 kg is revolving around
    earth at an altitude of 5000 km above the surface of
    earth. Earth has a mass of 5.98e24 kg and a radius of 6.38e6 m.
    Calculate the acceleration with which the satelite is revolving
    around earth.
    1. 3.08 m ⁄ s 2
    2. 5.178 m ⁄ s 2
    3. 5.816 m ⁄ s 2
    4. 0.807 m ⁄ s 2
    5. 2.023 m ⁄ s 2
    Answer: A

  10. An object of mass 2 kg is revolving in a vertical
    circle of radius 1.7 m. Calculate the minimum
    speed at the top of the circle by which the
    object can make it without the string slacking.
    1. 4.082 m ⁄ s
    2. 7.66 m ⁄ s
    3. 6.595 m ⁄ s
    4. 3.205 m ⁄ s
    5. 1.348 m ⁄ s
    Answer: A

  11. The principle of conservation of angular momentum states that
    1. the angular momentum of an object will be
      conserved if the net torque acting on the
      object is a constant.
    2. the angular momentum of an object will be
      conserved if all the forces acting on the
      object are conservative.
    3. the angular momentum of an object will be
      conserved if the net torque acting on the
      object is zero.
    4. the angular momentum of an object will be
      conserved if the net force acting on the
      object is zero.
    5. the angular momentum of an object will be
      conserved if the net force acting on the
      object is a constant.
    Answer: C

  12. A horizontal lever of length 1.6 m is pivoted
    at its mid-point. An downward force of 13 N is
    acting at the right end of the lever. Calculate
    the torque acting on the lever.
    1. -15.204 N m
    2. -5.636 N m
    3. -17.805 N m
    4. -4.175 N m
    5. -10.4 N m
    Answer: E

  13. A uniform horizontal lever of length 3.6 m is
    pivoted at its mid-point. The following forces
    are acting on the lever: a 0.53 N vertically upward force
    acting at the right end of the lever, a 11 N
    vertically upward force acting at the left end of the
    lever, and a 4 N vertically downward force (with downward
    vertical component) that makes an angle of 10 with
    the horizontal-right acting at a point on the lever 0.6 m
    away from the right end. Calculate the net
    torque acting on the lever.
    1. -2.599 N m
    2. -22.652 N m
    3. -5.838 N m
    4. -19.68 N m
    5. -16.588 N m
    Answer: D

  14. A uniform horizontal lever of length 5.23 m is pivoted
    at its mid-point. A vertically downward force of 6.71 N is
    acting at the right end of the lever. An unknown vertically
    downward force is acting at a dstance of 0.53 m
    to the left of the pivot. If the lever is in equilibrium,
    calculate the force exerted by the pivot
    (fulcurum) on the lever.
    1. 39.817 N
    2. 50.692 N
    3. 64.449 N
    4. 55.234 N
    5. 12.988 N
    Answer: A

  15. The center of gravity of two particles of masses
    20.33 kg and 9.87 kg is located at the point ( 3, 3 ) m.
    The 20.33 kg particle is located at the point ( -3, -4 ) m.
    Find the location of the 9.87 kg particle.
    1. ( 15.359, 17.418 ) m
    2. ( 4.899, 8.115 ) m
    3. ( 11.276, 17.418 ) m
    4. ( 11.276, 24.661 ) m
    5. ( 15.359, 24.661 ) m
    Answer: A

  16. An object is said to be in translational equilibrium if
    1. it is eithe at rest or rotating with a constant
      angular acceleration.
    2. it is either at rest or rotating with a constant
      angular velocity.
    3. it is either at rest or moving with a constant speed
    4. it is either at rest or moving with a constant acceleration
    5. it is either at rest or moving in a straight
      line with a constant speed.
    Answer: E

  17. An object of mass 4.2 kg is revolving in a circular
    path of radius 2.4 m with an angular acceleration of
    10.6 rad ⁄ s 2. Calculate the tangental force acting on
    the object.
    1. 119.078 N
    2. 174.694 N
    3. 153.548 N
    4. 61.169 N
    5. 106.848 N
    Answer: E

  18. Three particles of masses 10.3 kg, 1.5 kg and 5.7 kg are located
    at the points ( 9, 5 ) m, ( 13, 2 ) m, and ( -10, -4 ) m respectively.
    Calculate the angular momentum of this system of
    particles if they are revolving around the y-axis with
    an angular velocity of 21 rad ⁄ s.
    1. 49547.702 J s
    2. 34813.8 J s
    3. 25136.377 J s
    4. 4815.419 J s
    5. 53622.253 J s
    Answer: B

  19. A spherical object of mass 4 kg and radius
    0.028 m is rolling down an inclined plane of length
    2.5 m that makes an angle of 80 deg with the ground.
    Calculate its speed by the time it reaches the ground
    ( Ispehre = 2MR 2 / 5 )
    1. 8.542 m ⁄ s
    2. 5.871 m ⁄ s
    3. 3.746 m ⁄ s
    4. 9.278 m ⁄ s
    5. 7.042 m ⁄ s
    Answer: B

  20. The angular momentum of a spherical object revolving
    about an axis passing through its center increased
    from 7 J s to 29 J s in 3 s. Calculate the
    torque acting on it.
    1. 2.099 N m
    2. 4.267 N m
    3. 12.01 N m
    4. 7.333 N m
    5. 10.738 N m
    Answer: D

  21. A skater whose moment of inertia is 7.25 kg m 2 is revolving
    with an angular speed of 5.9 rad ⁄ s. She decreases her
    angular speed to 4.6 rad ⁄ s by extending her hands.
    Calculate her new moment of inertia.
    1. 12.659 kg m 2
    2. 9.299 kg m 2
    3. 1.318 kg m 2
    4. 6.883 kg m 2
    5. 14.483 kg m 2
    Answer: B

  22. The kind of stress where the force is applied
    perpendicularly on the entire surface area
    of an object is called
    1. parallel stress
    2. tensile stress
    3. shear stress
    4. normal stress
    5. bulk stress
    Answer: E

  23. An aluninum wire has a length of 8 m and a
    cross-sectional radius of 0.0025 m. Calculate the change in
    its length when an object of weight 60 N hangs from the wire.
    (modulus = 7e10 Pa)
    1. 47.722e-5 m
    2. 24.779e-5 m
    3. 40.209e-5 m
    4. 34.923e-5 m
    5. 51.296e-5 m
    Answer: D

  24. At what depth in an ocean would the pressure be
    5 times atmospheric pressure at sea level. (Assume the
    density of the ocean to be 1000 kg ⁄ m 3 )
    1. 29.471 m
    2. 41.347 m
    3. 76.998 m
    4. 57.674 m
    5. 45.626 m
    Answer: B

  25. In an open manometer filled with mercury (densty =
    13600 kg ⁄ m 3 ), the level of mercury column in the air side is
    0.09 m higher than that in the gas side. Determine the pressure
    of the gas. Atmospheric pressure is 1e5 Pa.
    1. 14394.24 Pa
    2. 88004.8 Pa
    3. 13194.72 Pa
    4. 11995.2 Pa
    5. 111995.2 Pa
    Answer: E

  26. Determine the atmospheric pressure at a place
    where a mercury (density = 13600 kg ⁄ m 3 ) barometer
    rises by 0.4 m.
    1. 53312 Pa
    2. 6013.585 Pa
    3. 81281.95 Pa
    4. 45180.263 Pa
    5. 63628.154 Pa
    Answer: A

  27. Two tubes of different cros-sectional areasare
    connected together horizontally. Which of
    the following is a true statement about a
    fluid flowing through the tubes.
    1. The speed of the fluid in the narrower tube is
      greater than the speed of the fluid in the
      wider tube.
    2. The pressure of the fluid in the narrower tube
      is greater than that in the wider tube.
    3. The amount of fluid that leaves the wider tube
      is greater than the amount of fluid that
      enters the narrower tube in the same interval
      of time.
    4. The speed of the fluid in the narrower tube is
      less than the speed of the fluid in the wider tube.
    5. The amount of fluid that leaves the wider tube
      is less than the amount of fluid that enters
      the narrower tube in the same interval of time.
    Answer: A

  28. An object of volume 9e-6 m 3 and density 9000 kg ⁄ m 3 is
    immersed inside a fluid of density 2500 kg ⁄ m 3. Calculate
    the force exerted by the fluid on the object.
    1. 0.31 N
    2. 0.355 N
    3. 0.168 N
    4. 0.221 N
    5. 0.038 N
    Answer: D

  29. An object of volume 7e-5 m 3 and density 750 kg ⁄ m 3 is floating in a
    fluid of density 2500 kg m 3. Calculate the volume of the object
    exposed above the surface of the fluid.
    1. 0.543e-5 m 3
    2. 4.9e-5 m 3
    3. 2.797e-5 m 3
    4. 7.178e-5 m 3
    5. 9.16e-5 m 3
    Answer: B

  30. Tube 1 and tube 2 are connected together. A fluid
    flowing through these tubes has a speed of 4 m ⁄ s in tube 1
    and a speed of 19 m ⁄ s in tube 2. Calculate the ratio
    of the cross-sectional radius of tube 2 to the cross-sectional
    radius of tube 1.
    1. 0.232
    2. 0.687
    3. 0.459
    4. 0.086
    5. 0.534
    Answer: C

  31. Two tubes of different cross-sectional radii are
    connected together with the first tube
    elevated 0.7 m above the second tube. A fluid of density
    2000 kg ⁄ m 3 enters the first tube with a speed of 0.75 m ⁄ s. The
    cross-sectional radius of the first tube is 0.02 m
    and that of the second tube is 0.16 m. If the pressure
    of the fluid in the first tube is 2e3 Pa, calculate
    the pressure of the fluid in the second tube.
    1. 4040.917 Pa
    2. 24330.974 Pa
    3. 20620.682 Pa
    4. 16282.363 Pa
    5. 10684.351 Pa
    Answer: D