Conceptual Questions

  1. An object has density ρ.

    1. Suppose each of the object’s three dimensions is increased by a factor of 2 without changing the material of which the object is made. Will the density change? If so, by what factor? Explain.

    2. Suppose each of the object’s three dimensions is increased by a factor of 2 without changing the object’s mass. Will the density change? If so, by what factor? Explain.

  2. Rank in order, from largest to smallest, the pressures at points 1, 2, and 3 in FIGURE Q14.2. Explain.

    FIGURE Q14.2

    The figure illustrates six pressure points depicted as dots labeled 1 to 6 in a tank filled with a liquid.

  3. Rank in order, from largest to smallest, the pressures at points 4, 5, and 6 in FIGURE Q14.2. Explain.

  4. FIGURE Q14.4 shows two rectangular tanks, A and B, full of water. They have equal depths and equal thicknesses (the dimension into the page) but different widths.

    1. Compare the forces the water exerts on the bottoms of the tanks. Is FA larger than, smaller than, or equal to FB? Explain.

    2. Compare the forces the water exerts on the sides of the tanks. Is FA larger than, smaller than, or equal to FB? Explain.

    FIGURE Q14.4

    The figure illustrates two rectangular tanks labeled "A" and B.

  5. In FIGURE Q14.5, is p1 larger than, smaller than, or equal to p2? Explain.

    FIGURE Q14.5

    The figure illustrates a ship floating in the sea.

  6. Rank in order, from largest to smallest, the densities of blocks A, B, and C in FIGURE Q14.6. Explain.

    FIGURE Q14.6

    The figure illustrates three blocks labeled "A", B, and C floating partially submerged in a liquid.

  7. Blocks A, B, and C in FIGURE Q14.7 have the same volume. Rank in order, from largest to smallest, the sizes of the buoyant forces FA , FB , and FC  on A, B, and C. Explain.

    FIGURE Q14.7

    The figure illustrates three squares labeled "A", B, and C floating at different heights in a container of liquid.

  8. Blocks A, B, and C in FIGURE Q14.7 have the same density. Rank in order, from largest to smallest, the sizes of the buoyant forces FA , FB , and FC on A, B, and C. Explain.

  9. The two identical beakers in FIGURE Q14.9 are filled to the same height with water. Beaker B has a plastic sphere floating in it. Which beaker, with all its contents, weighs more? Or are they equal? Explain.

    FIGURE Q14.9

    The figure illustrates two beakers labeled "A" and B having the same levels of water.

  10. Gas flows through the pipe of FIGURE Q14.10. You can’t see into the pipe to know how the inner diameter changes. Rank in order, from largest to smallest, the gas speeds v1 , v2 , and v3 at points 1, 2, and 3. Explain.

    FIGURE Q14.10

    The figure illustrates gas flow through a tube.

  11. Wind blows over the house in FIGURE Q14.11. A window on the ground floor is open. Is there an airflow through the house? If so, does the air flow in the window and out the chimney, or in the chimney and out the window? Explain.

    FIGURE Q14.11

    The figure illustrates a house. Two horizontal arrows labeled Wind above the house point toward the right.

  12. A 2000 N force stretches a wire by 1 mm. A second wire of the same material is twice as long and has twice the diameter. How much force is needed to stretch it by 1 mm? Explain.

  13. A wire is stretched right to the breaking point by a 5000 N force. A longer wire made of the same material has the same diameter. Is the force that will stretch it right to the breaking point larger than, smaller than, or equal to 5000 N? Explain.