37. Smoking was a common habit in the United States in times past, and nonsmokers riding in cars where another passenger had lit up quickly learned to open their window a crack while the car was moving to exhaust the smoke from the compartment. Why does this action help to draw the smoke out of the car? Explain using principles of fluid physics.

41. Five containers each hold the same volume of various liquids. Five blocks composed of various solids are fully submerged, one in each of the five containers. The blocks all have the same size and are all held at the same depth in the containers. The volume of each block is one-fourth the volume of the liquids in the containers. For the given combinations of block mass, Mb, and liquid mass, Ml, rank the buoyant forces on the blocks from largest to smallest. If two or more circumstances yield the same buoyant forces, give them the same ranking. Explain your reasoning in setting your ordering.

(a) Mb = 0.04 kg; Ml = 0.20 kg.

(b) Mb = 0.03 kg; Ml = 0.15 kg.

(c) Mb = 0.04 kg; Ml = 0.12 kg.

(d) Mb = 0.02 kg; Ml = 0.08 kg.

(e) Mb = 0.03 kg; Ml = 0.12 kg.

1. A grain silo is filled with 2 million pounds of wheat. The area of the silo's floor is 400 ft2. Find the pressure on the floor in pounds per square foot and in psi.

3. A large truck tire is inflated to a gauge pressure of 80 psi. The total area of one sidewall of the tire is 1,200 in.2. What is the outward force on the sidewall because of the air pressure?

5. A box-shaped metal can has dimensions 8 in. by 4 in. by 10 in. high. All of the air inside the can is removed with a vacuum pump. Assuming normal atmospheric pressure outside the can, find the total force on one of the 8-by-10-in. sides.

7. A large chunk of metal has a mass of 393 kg, and its volume is measured to be 0.05 m3.

(a) Find the metal's mass density and weight density in SI units.

(b) What kind of metal is it?

9. A large tanker truck can carry 20 tons (40,000 lb) of liquid.

(a) What volume of water can it carry?

(b) What volume of gasoline can it carry?

11. A large balloon used to sample the upper atmosphere is filled with 900 m3 of helium. What is the mass of the helium?