Chapter 3

Question 1

a nonsolid state of matter in which the atoms or molecules are free to move past each, as in a gas or liquid

Answer 1

fluid

Question 2

the amount of force exerted per unit area of a surface

Answer 2

pressure

Question 3

the SI unit of pressure (symbol, Pa)

Answer 3

pascal

Question 4

the pressure caused by the weight of the atmosphere

Answer 4

atmospheric pressure

Question 5

the upward force that keeps an object immersed in or floating on a liquid

Answer 5

buoyant force

Question 6

the principle that states that the buoyant force on an object in a fluid is an upward force equal to the weight of the volume of fluid that the object displaces

Answer 6

Archimedes’ principle

Question 7

the principle that states that the pressure in a fluid decreases as the fluid’s velocity increases

Answer 7

Bernoulli’s principle

Question 8

an upward force on an object that moves in a fluid

Answer 8

lift

Question 9

the pushing or pulling force exerted by the engine of an aircraft or rocket

Answer 9

thrust

Question 10

a force parallel to the velocity of the flow; it opposes the direction of an aircraft and, in combination with thrust, determines the speed of the aircraft

Answer 10

drag

Question 11

the principle that states that a fluid in equilibrium contained in a vessel exerts a pressure of equal intensity in all directions

Answer 11

Pascal’s principle