Directed Reading Chapter 7 Section 1 Name: ______Period: ___ Date: ____
Define 1-6:
1. Fluid - ______
2. Pressure - ______
3. Pascal - ______
4. Atmospheric pressure - ______
5. Buoyant Force- ______
6. Archimede’s Principle- ______
Section 1- Fluids and Pressure
7. Name 2 types of fluids ______& ______
8. Force divided by area equals ______
9. The force of one Newton exerted over an area of one square meter is one ______.
Match the correct description with the correct term. Write the word in space provided.
10. ______pressure caused by the weight of the atmosphere
11. ______percentage of gases found within 10 km of Earth’s surface
12. ______force that hold the atmosphere in place
13. ______number of Newton’s pressing on every cm2 of your body
Number each location listed from 1-5 in order of lowest to highest pressure.
14. _____ Mt. Everest’s peak
15. _____ La Paz, Bolivia
16. _____ airplane at 12,000 m
17. _____ beach at sea level
18. _____ space shuttle at 150,000 m above sea level
19. Water pressure increases as
a. gravity decreases b. air pressure decreases c. depth increases d. particles collide
20. Water pressure and atmospheric pressure affect total pressure on objects that are
a. underground b. above sea level c. in a car d. underwater
21. Water is about 1,000 times more dense than
a. air b. pressure c. gravity d. oil
22. Water pressure does not depend on
a. atmospheric pressure b. amount of fluid present c. air pockets d. gravity
23. The amount of matter in a given volume, or mass per unit volume is called ______.
24. Which exerts more pressure, water or air? ______
25. The pressure at 500 m below the water’s surface is about ______.
26. The pressure at 8,000 m below the water’s surface is about ______.
27. Pumping up a tire ______the amount of air inside the tire.
28. What happens to pressure as you go deeper in a fluid? ______
29. What happens to fluids in your body when the atmospheric pressure changes?
a. They adjust to equal pressure. b. They maintain low pressure.
c. They maintain high pressure. d. They don’t react to pressure.
30. What does NOT affect the total pressure on an underwater object?
a. water depth b. water pressure
c. atmospheric pressure d. total amount of fluid present
31. How much more dense is water than air?
a. 10 X b. 100 X c. 1,000 X d. 8,000 X
32. When you drink through a straw, how does the liquid move?
a. through the atmosphere b. from high to low pressure
c. from low to high pressure d. through muscles
33. What happens in the lungs when you exhale?
a. The air moves from low pressure (outside) to high pressure (outside).
b. Lung pressure decreases.
c. The space in your lungs increases.
d. The air moves from high pressure (in the lungs) to low pressure ( outside).
Section 2 – Buoyant Force
34. In a fluid, buoyant force exists because the pressure is greater at the ______of an object than the pressure at the top.
35. The weight of displaced fluid determines the ______of an object.
36. If the weight of the water an object displaces is equal to the weight of the object, the object (sinks, floats or is buoyed up) ______.
37. If the weight of the water an object displaces is less than the weight of the object, the object (sinks, floats or is buoyed up) ______.
38. If the weight of the water an object displaces is greater than the object’s weight, the object (sinks, floats or is buoyed up) ______.
Match the correct description with the correct formula. Write the letter to the left of the number.
__39. When a rock sinks a. Buoyant force is less than weight of object.
__40. When a duck floats b. Buoyant force equals weight of object.
__41. When a fish is suspended in the water c. Buoyant force is greater than weight of object.
42. Pressure increases as ______increases.
43. The principle used to determine buoyant force is called ______.
44. The buoyant force is determined by the ______of the displaced water.
45. An object that weighs more than the buoyant force on it will ______.
46. An object whose weight equals the buoyant force will ______.
47. Why don’t most substances float in air?
a. Air is too dense. b. Most substances are denser than air.
c. Air weighs too much. d. Volume is too great.
48. What is less dense than air?
a. water b. ice
c. helium d. a duck
49. What is it about a ship that allows it to float?
a. its passengers b. its shape
c. its hull d. its material
50. What increases when steel is shaped into a hollow form?
a. its weight b. its volume
c. its density d. its mass
51. What is the organ that keeps some fish from sinking?
a. gills b. swim bladder
c. lungs d. brain
Read the description. Then, draw a line from the dot next to each description to the matching term.
52. air-filled ballast tanks ● a. diving submarine
53. open ballast tanks ● b. rising submarine
54. pumping air into closed ballast tanks ● c. floating submarine