Practice Quiz 18

Choose the best answer

  1. Archimedes principle states that
    1. the pressure exerted by a fluid increases with depth
    2. An object sinks in a fluid if its density is
      greater than the density of the fluid.
    3. an object immersed in a fluid is acted upon by
      an upward force equal to the weight of the
      displaced fluid.
    4. an object immersed in a fluid is acted upon by
      an upward force equal to the weight of the object.
    5. an object immersed in a fluid is acted upon by
      a downward force equal to the weight of the object.
    Answer: C

  2. An object will float in a fluid partially
    immersed if
    1. its density is less than the densty of the fluid.
    2. its density is less or equal to the density of
      the fluid
    3. its density is greater or equal to the density
      of the fluid
    4. its density is greater than the density of the fluid.
    5. its density is equal to the density of the fluid
    Answer: A

  3. An object of volume 9e-6 m 3 and density 8000 kg ⁄ m 3 is
    immersed inside a fluid of density 2000 kg ⁄ m 3. Calculate
    the force exerted by the fluid on the object.
    1. 0.022 N
    2. 0.176 N
    3. 0.318 N
    4. 0.113 N
    5. 0.212 N
    Answer: B

  4. An object of volume 6e-4 m 3 is immersed in a fluid
    of density 7750 kg ⁄ m 3. If the weight of the object inside
    the fluid is 8.5 N, calculate the density of the object.
    1. 6181.511 kg ⁄ m 3
    2. 14010.496 kg ⁄ m 3
    3. 9195.578 kg ⁄ m 3
    4. 15678.099 kg ⁄ m 3
    5. 10903.692 kg ⁄ m 3
    Answer: C

  5. Calculate the density of an object that floats in a fluid
    of density 4500 kg ⁄ m 3 with 90 % of its volume
    immersed in the fluid.
    1. 7054.81 kg ⁄ m 3
    2. 2048.066 kg ⁄ m 3
    3. 5057.838 kg ⁄ m 3
    4. 950.539 kg ⁄ m 3
    5. 4050 kg ⁄ m 3
    Answer: E

  6. An object of volume 9.5e-5 m 3 is floating in a fluid of
    density 4000 kg ⁄ m 3 with 3.5e-5 m 3 of its volume exposed
    above the surface of the fluid. Calculate the density
    of the object.
    1. 3696.011 kg ⁄ m 3
    2. 2794.77 kg ⁄ m 3
    3. 2526.316 kg ⁄ m 3
    4. 4300.895 kg ⁄ m 3
    5. 629.64 kg ⁄ m 3
    Answer: C

  7. Tube 1 and tube 2 of cross-sectional radii of 0.02 m
    and 0.03 m respectively are connected together.
    When a fluid flows through these tubes, calculate the
    ratio of the speed of the fluid in tube 2 to the speed
    of the fluid in tube 1.
    1. 0.444
    2. 0.248
    3. 0.098
    4. 0.354
    5. 0.199
    Answer: A

  8. A tube of cross-sectional-radius 0.19 m is connected wth
    a tube of cross-sectional radius 0.12 m. If the speed
    of a fluid in the 0.19 m cross-sectional radius tube
    is 24 m ⁄ s, calculate the speed of the fluid in
    the 0.12 m cross-sectional radius tube.
    1. 31.797 m ⁄ s
    2. 52.416 m ⁄ s
    3. 60.167 m ⁄ s
    4. 85.118 m ⁄ s
    5. 102.641 m ⁄ s
    Answer: C

  9. Two tubes of different cross-sectional radii are
    connected horizontally. The speed of a fluid of
    density 2500 kg ⁄ m 3 in the first and second tube respectively
    are 1.6 m ⁄ s and 0.5 m ⁄ s. If the pressure of the fluid
    in the first tube is 3e3 Pa, calculate the pressure
    of the fluid in the second tube.
    1. 5887.5 Pa
    2. 4182.923 Pa
    3. 2531.452 Pa
    4. 8934.123 Pa
    5. 1284.02 Pa
    Answer: A

  10. Two tubes of different cross-sectional radii are
    connected together with the first tube
    elevated 0.8 m above the second tube. The speed of a fluid of
    density 1750 kg ⁄ m 3 in the first and second tube respectively
    are 2.0 m ⁄ s and 0.2 m ⁄ s. If the pressure of the fluid
    in the first tube is 7e3 Pa, calculate the pressure
    of the fluid in the second tube.
    1. 38296.701 Pa
    2. 31527.484 Pa
    3. 24185 Pa
    4. 26854.142 Pa
    5. 11756.38 Pa
    Answer: C