1. Physics Practice Questions "Exam 7 Practice"

both A and C

14) Pressure in a liquid depends on the __________. A) depth of the measuring point. B) volume of the liquid. C) density of the liquid. D) mass of the liquid. E) both A and C

bottom of the object

15) Water pressure on a submerged object is greatest against the __________. A) Water pressure is the same against all surfaces of the object B) top of the object C) sides of the object D) bottom of the object E) none of the above

surface area of the water

16) The pressure at the bottom of a jug filled with water does NOT depend on the __________. A) depth of the liquid B) acceleration due to gravity C) density of water D) surface area of the water E) none of the above

weight of the fluid displaced

17) Archimedes' principle says that an object is buoyed up by a force that is equal to the __________. A) volume of the fluid displaced B) weight of the fluid displaced C) mass of the fluid displaced D) mass of the object E) none of the above

Neither place -- the buoyant force is independent of depth

18) Where is the buoyant force on a submerged rock greater, near the surface of the fluid or 10 m below the surface? A) 10 m below the surface B) Near the surface C) Neither place -- the buoyant force is independent of depth

True

19) The reason objects immersed in a fluid experience an upward buoyant force is because fluid pressure on the bottom of the object is greater than fluid pressure on the top of the object. A) True B) False

you and the jacket together have density less than your density alone

20) The reason a life jacket helps you float is that __________. A) the jacket repels water B) the jacket has the same density as an average human C) the jacket makes you weigh less D) you and the jacket together have density less than your density alone.

the density of salt water exceeds the density of egg

21) An egg is placed at the bottom of a bowl filled with water. Salt is slowly added to the water until the egg rises and floats. From this experiment, one can conclude that __________. A) the density of salt water exceeds the density of egg. B) salt sinks to the bottom. C) calcium in the eggshell is repelled by sodium chloride. D) buoyant forces do not always act upward. E) none of the above

neither float nor sink, but stay anywhere it is put

22) If an object has a density equal to the density of water, it will __________. A) float B) neither float nor sink, but stay anywhere it is put C) sink

the iron displaces more water than it would if it were in a solid block

23) The reason an iron ship doesn't sink is that __________. A) air inside decreases it's weight B) the iron displaces more water than it would if it were in a solid block C) iron is less dense than water D) Nonsense -- an iron ship will always sink

it displaces a weight of water equal to its own weight

24) When first put in water, a plastic toy boat will sink until __________. A) it displaces a weight of water equal to its own weight B) it displaces a volume of water equal to its own volume C) the water density equals the density of the boat D) the buoyant force equals the volume of the boat E) the buoyant force equals the density of the boat

equal to the weight of the other bucket

25) Two equal-sized buckets are filled to the top with water. One of the buckets has a piece of wood floating in it, making its total weight __________. A) equal to the weight of the other bucket B) less than the weight of the other bucket C) more than the weight of the other bucket

greater on the lead

26) A block of balsa wood floats on water while a same-size block of lead lies submerged in the water. The buoyant force is __________. A) greater of the wood. B) greater on the lead. C) the same for both

remain unchanged

27) A boat loaded with a barrel of water floats in a swimming pool. When the water in the barrel is poured overboard, the swimming pool level will __________. A) fall B) rise C) remain unchanged

remains the same

28) When an ice cube in a glass of water melts, the water level __________. A) falls B) rises C) remains the same

are transmitted to all points in the fluid

29) Pascal's principle says that changes in pressure at any point in an enclosed fluid __________. A) are transmitted to all points in the fluid B) remain only at the point C) quickly diminish from point to point in the fluid D) are transmitted only to points below it E) are transmitted only to points close to it

smaller-diameter piston

30) A hydraulic arrangement consists of a water-filled U-tube that is wider on one end than on the other. Pistons are fitted in both ends. To multiply an input force, the input end should be the one having the __________. A) smaller-diameter piston B) larger-diameter piston C) It doesn't matter what relative size the piston is.

the distance through which the force acts

31) A hydraulic press multiplies a force by 100. This multiplication is done at the expense of __________. A) the distance through which the force acts. B) energy, which decreases by a factor of 100. C) the time over which the force acts, which is extended by a factor of 100. D) the mechanism providing the force. E) none of the above

1 N

32) Suppose a stone weighs 3 N in the air, but in water it weighs only 2 N. What is the buoyant force acting on the stone? A) 3 N B) 2 N C) 4 N D) 5 N E) 1 N

20 N

33) One liter of water weighs about 10 N. Suppose a 2-liter container is filled with 266 N of mercury and then lowered into a container of water. Assuming the container is completely submerged, what is the buoyant force acting on it? A) 26.6 N B) 266 N C) 133 N D) 20 N E) 10 N

50 N

34) A 5000-N car is lifted on a hydraulic piston of area 2000 square centimeters. How much force on a 20-square-centimeter piston is needed to lift the car? A) 250 N B) 5000 N C) 50 N D) 2000 N E) 500 N

distances between molecules are larger

35) The main difference between gases and liquids is that in a gas __________. A) molecules collide more often. B) forces between molecules are larger. C) molecules are moving faster. D) distances between molecules are larger. E) all of the above

none of the above

36) In the top of a barometer there is a space that is filled with __________. A) dense mercury vapor. B) air. C) water vapor. D) helium. E) none of the above

taller

37) A barometer that uses water instead of mercury will be __________. A) shorter B) taller C) the same height

10.3 m

38) About how high can water theoretically be lifted by a vacuum pump at sea level? A) Less than 10.3 m B) More than 10.3 m C) 10.3 m

increases by a factor of 2

39) If you squeeze a balloon to one half its original size, the pressure inside __________. A) increases by a factor of 2 B) increases by a factor of 4 C) stays the same D) decreases by a factor of 2 E) decreases by a factor of 4

greater than air pressure outside the balloon

40) Gas pressure inside an inflated stretched balloon is __________. A) less than air pressure outside the balloon B) greater than air pressure outside the balloon C) equal to air pressure outside the balloon

increases

41) As a woman holding her breath swims deeper and deeper beneath the water's surface, her density __________. A) decreases B) remains the same C) increases

buoyant force

42) In a vacuum on earth, an object has no __________. A) heat B) temperature C) mass D) weight E) buoyant force

sink

43) Consider an air-filled balloon, weighted with a stone, that just barely floats in water. When the balloon is pushed beneath the surface, say about a meter deep, and then released, it will __________. A) stay where it is B) sink C) float back to the surface

Neither -- they both experience the same buoyant force

44) Which has the larger buoyant force, a balloon filled with helium or the same size balloon filled with air? A) The helium balloon B) The air balloon C) Neither -- they both experience the same buoyant force.

The air balloon

45) Which has more weight, a balloon filled with helium or the same size balloon filled with air? A) The air balloon B) The helium balloon C) Neither -- they both have the same weight.

1 ton

46) A 1-ton dirigible hovers in the air. The buoyant force acting on it is __________. A) less than 1 ton B) 1 ton C) zero D) more than 1 ton

fall

47) If you are standing on the moon and release a balloon filled with helium gas, the balloon will __________. A) neither rise nor fall B) rise C) fall

both A and B

48) The lift that supports an airplane wing is a consequence of __________. A) Bernoulli's principle. B) Newton's third law. C) both A and B. D) none of the above

there is less pressure inside the curtain

49) The reason a shower curtain will pull to the inside of a bathtub during a shower is that __________. A) there is less air inside the curtain B) there is more water inside the curtain C) there is more pressure inside the curtain D) there is more air inside the curtain E) there is less pressure inside the curtain

move to the left

50) A car with closed windows makes a left-hand turn. A helium-filled balloon in the car will __________. A) move to the right B) move to the front C) move to the back D) move to the left E) stay in the same place