19. If Earth's atmosphere warmed up and expanded to a larger total volume but its total mass did not change, would this affect the atmospheric pressure at sea level? Would this affect the pressure at the top of Mount Everest? Explain.

21. Explain how a barometer can be used to measure altitude.

25. What substances would sink in gasoline but float in water?

27. A ship on a large river approaches a bridge, and the captain notices that the ship is about a foot too tall to fit under the bridge. A crew member suggests pumping water from the river into an empty tank on the ship. Would this help? Why or why not?

29. A brick is tied to a balloon filled with air and then tossed into the ocean. As the balloon is pulled downward by the brick, the buoyant force on it decreases. Why?

31. What is Pascal's principle?

33. What important thing happens when the speed of a moving fluid increases?

35. How does a perfume atomizer make use of Bernoulli's principle?