Forces in Fluids

Question 1

fluid

Answer 1

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

Question 2

pressure

Answer 2

the amount of force exerted per unit area of a surface

Question 3

pascal

Answer 3

the SI unit for pressure

Question 4

atmospheric pressure

Answer 4

the pressure caused by the weight of the atmosphere

Question 5

buoyant force

Answer 5

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

Question 6

Archimedes’ principle

Answer 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

Question 7

Bernoulli’s principle

Answer 7

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

Question 8

lift

Answer 8

an upward force on an object that moves in a fluid

Question 9

thrust

Answer 9

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

Question 10

drag

Answer 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

Question 11

Pascal’s principle

Answer 11

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