Quiz Practice (Ch 14)
1) A plasma differs from a gas in that
A) its molecules are farther apart.
B) it is hotter than a gas.
C) it is electrically conducting.
D) its atoms are boosted to higher atomic numbers.
E) all of these
Answer: C
2) About what percentage of the molecules that make up the atmosphere are below an aircraft
that flies at an altitude of 6 kilometers?
A) 20%
B) 30%
C) 40%
D) 50%
E) more than 50%
Answer: E
3) What is the approximate mass of a 1-square-centimeter column of air that extends from sea
level to the top of the atmosphere?
A) 1 gram
B) 1 kilogram
C) 10 kilograms
D) 100 kilograms
Answer: B
4) A balloon is buoyed up with a force equal to the
A) weight of air it displaces.
B) density of surrounding air.
C) atmospheric pressure.
D) weight of the balloon and contents.
E) all of these
Answer: A
5) A bubble of air released from the bottom of a lake
A) rises to the top at constant volume.
B) becomes smaller as it rises.
C) becomes larger as it rises.
D) alternately expands and contracts as it rises.
E) none of these
Answer: C
6) A common 5-liter metal can will float in air if it is
A) evacuated of air.
B) filled with a very large amount of helium.
C) thrown high enough.
D) A can will not float in air unless the displaced air weighs more than the can and its contents.
Answer: D
7) The air in this room has
A) mass.
B) weight.
C) energy.
D) all of these
E) none of these
Answer: D
8) The flight of a blimp best illustrates
A) the principle of Archimedes.
B) Pascal's principle.
C) Bernoulli's principle.
D) Boyle's law.
Answer: A
9) The faster a fluid moves, the
A) greater its internal pressure.
B) less its internal pressure.
C) internal pressure is unaffected.
Answer: B
10) If a strong wind from the west breaks a window in the north wall of a house, most of the
glass will fall
A) upward.
B) inside the house.
C) outside the house.
Answer: C
11) A column that extends from sea level to the top of the atmosphere contains a certain mass of
air. If the same column instead had the same mass of mercury in it, the height of the mercury
column would be
A) 1/13.6 times the height of the atmosphere.
B) about 3/4 meter.
C) 10.3 meters.
D) about 5.6 kilometers.
Answer: B
12) Consider two mercury barometers, one with twice the cross-sectional area of the other.
Neglecting capillarity, mercury in the smaller tube will rise
A) the same height as in the larger tube.
B) twice as high as mercury in the larger tube.
C) four times as high as mercury in the larger tube.
D) more than four times as high as in the larger tube.
E) none of these
Answer: A
13) As a high-altitude balloon sinks lower and lower into the atmosphere, it undergoes a decrease
in
A) volume.
B) density.
C) weight.
D) mass.
E) none of these
Answer: A
14) A helium-filled balloon released in the atmosphere will rise until
A) the pressure inside the balloon equals atmospheric pressure.
B) atmospheric pressure on the bottom of the balloon equals atmospheric pressure on the top of
the balloon.
C) the balloon and surrounding air have equal densities.
D) all of these
E) none of these
Answer: C
15) Alcohol is less dense than water. If alcohol is used to make a barometer on a day when
atmospheric pressure is normal, the height of the alcohol column would be
A) less than 10.3 m.
B) more than 10.3 m.
C) 10.3 m.
Answer: B
16) Compared to the buoyant force of the atmosphere on a 1-kilogram helium-filled balloon, the
buoyant force of the atmosphere on a nearby 1-kilogram solid iron block is
A) considerably less.
B) considerably more.
C) the same.
Answer: A
17) When gas in a container is squeezed to half its volume, its density
A) halves.
B) doubles.
C) quadruples.
D) remains the same.
Answer: B
18) The depth to which an inverted drinking glass must be pushed beneath the surface of water
so that the volume of enclosed air is squeezed to half is
A) 76 cm.
B) 10.3 m.
C) 14.7 m.
D) 20.6 m.
E) 29.4 m.
Answer: B
19) An umbrella tends to move upwards on a windy day principally because
A) air gets trapped under the umbrella, warms, and rises.
B) buoyancy increases with increasing wind speed.
C) air pressure is reduced over the curved top surface.
D) all of these
Answer: C
20) The Bernoulli effect causes passing ships to be drawn together when the ships are close and
moving in
A) the same direction.
B) opposite directions.
C) either the same or opposite directions.
Answer: C
21) In a vacuum, an object has no
A) buoyant force.
B) mass.
C) weight.
D) temperature.
E) all of these
Answer: A
22) Suspend a pair of Ping-Pong balls from two strings so there is a small space between them. If
you blow air between the balls, they will swing
A) toward each other.
B) apart from each other.
C) away from the air stream, but not necessarily toward or apart from each other.
Answer: A
23) Assuming no change in temperature, as a freely expanding helium-filled balloon rises in the
atmosphere, the buoyant force that acts on it
A) increases.
B) decreases.
C) remains nearly the same for a long way.
Answer: C
24) 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 left.
C) move to the front.
D) move to the back.
E) not move.
Answer: B
25) In a vacuum a marshmallow becomes
A) larger.
B) smaller.
C) flat.
D) a hollow shell.
E) none of the above choices
Answer: A