Deck 14: Gases and Plasmas

Question 1

The weight of a 1-square-meter column of air that extends from sea level to the top of the atmosphere is

A)101 N.
B)10,100 N.
C)101,000 N.
D)101,000,000 N.

Answer 1

101,000 N.

Question 2

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 2

the principle of Archimedes.

Question 3

When water is turned on in a shower,the shower curtain moves towards the water.This has to do with

A)capillary action.
B)surface tension.
C)heat capacity.
D)pressure of a moving fluid.
E)none of these

Answer 3

pressure of a moving fluid.

Question 4

In drinking soda or water through a straw,we make use of

A)capillary action.
B)surface tension.
C)atmospheric pressure.
D)Bernoulli's principle.
E)none of these

Question 5

The energy source responsible for the motion of molecules that make up the atmosphere is

A)their own natural kinetic energy.
B)the pressure caused by the weight of air.
C)atmospheric tides.
D)solar power.

Question 6

Airplane flight best illustrates

A)Archimedes' principle.
B)Pascal's principle.
C)Bernoulli's principle.
D)Boyle's law.

Question 7

About how high can water be theoretically lifted by a vacuum pump at sea level?

A)less than 10.3 m
B)more than 10.3 m
C)10.3 m

Question 8

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.

Question 9

The faster a fluid moves,the

A)greater its internal pressure.
B)less its internal pressure.
C)internal pressure is unaffected.

Question 10

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

Question 11

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%

Question 12

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

Question 13

A one-ton blimp hovers in the air.The buoyant force acting on it is

A)zero.
B)one ton.
C)less than one ton.
D)more than one ton.

Question 14

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.

Question 15

As a helium-filled balloon rises in the air,it becomes

A)bigger.
B)more dense.
C)heavier.
D)all of these
E)none of these

Question 16

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

Question 17

The air in this room has

A)mass.
B)weight.
C)energy.
D)all of these
E)none of these

Question 18

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

Question 19

Atmospheric molecules do not fly off into outer space because of

A)their relatively high speeds.
B)their relatively low densities.
C)Earth gravitation.
D)cohesive forces.

Question 20

Atmospheric pressure is caused by the

A)density of the atmosphere.
B)weight of the atmosphere.
C)temperature of the atmosphere.
D)effect of the sun's energy on the atmosphere.

Question 21

Use the following figure to answer the question:
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.

Question 22

A swimmer cannot use a long hose to snorkel more than a meter deep because air

A)in the lungs cannot easily be expelled.
B)tends to liquify in the snorkel tube.
C)is buoyed up leaving the swimmer breathless.
D)at the surface will not freely enter the higher-pressure region in the compressed lungs.
E)all of these

Question 23

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

Question 24

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.

Question 25

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.

Question 26

Two vertical tubes of equal cross-sectional areas are filled with water and mercury.If water is filled to a depth of 10.3 m and mercury to a depth of 0.76 m,both liquids have equal

A)volumes.
B)densities.
C)weights.
D)viscosity.
E)none of these

Question 27

As a woman holding her breath swims deeper and deeper beneath the water's surface,her density

A)increases.
B)decreases.
C)remains the same.

Question 28

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

Question 29

Wind blowing over the top of a hill

A)increases atmospheric pressure there.
B)decreases atmospheric pressure there.
C)does not affect atmospheric pressure there.

Question 30

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

Question 31

As a balloon rises higher and higher into the atmosphere,its

A)volume decreases.
B)density increases.
C)weight increases.
D)mass decreases.
E)none of these

Question 32

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.

Question 33

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 water in it,the height of the water 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.

Question 34

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.

Question 35

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

Question 36

When gas in a container is squeezed to half its volume,its density

A)halves.
B)doubles.
C)quadruples.
D)remains the same.

Question 37

Compared to the buoyant force of the atmosphere on a 1-liter helium-filled balloon,the buoyant force of the atmosphere on a nearby 1-liter solid iron block is

A)considerably less.
B)considerably more.
C)the same.

Question 38

When gas in a container is squeezed to half its volume and the temperature remains the same,the gas pressure

A)halves.
B)doubles.
C)quadruples.
D)remains the same.

Question 39

Gas pressure inside an inflated stretched balloon is actually

A)less than air pressure outside the balloon.
B)equal to air pressure outside the balloon.
C)greater than air pressure outside the balloon.
D)impossible to determine without knowing the type of gas.

Question 40

A suction cup sticks to a wall.It is

A)pulled to the wall by the vacuum.
B)pushed to the wall by the atmosphere.
C)both of these
D)neither of these

Question 41

Which of the following is an example of matter in a plasma state?

A)dry ice
B)a torch flame
C)molten lava
D)liquid hydrogen
E)none of these

Question 42

The main difference between gases and plasmas has to do with

A)the kinds of elements involved.
B)interatomic spacing.
C)electrical conduction.
D)fluid pressure.
E)the proportion of matter to antimatter in the universe.

Question 43

When a common fluorescent lamp is on,the mercury vapor inside is actually in a

A)gaseous state.
B)liquid state.
C)plasma state.
D)solid state.
E)none of these

Question 44

Which of the following bodies is comprised mostly of plasma?

A)Earth
B)Moon
C)Sun
D)all of these
E)none of these

Question 45

An empty jar is pushed open-side downward into water so that air trapped in it cannot get out.As it is pushed deeper,the buoyant force on the jar

A)increases.
B)decreases.
C)increases,then decreases.
D)decreases,then increases.
E)remains the same.

Question 46

Most of the matter in the universe is in the

A)solid state.
B)liquid state.
C)gaseous state.
D)plasma state.
E)none of these

Question 47

Plasmas are a central part of power generation in

A)MHD generators.
B)turbo generators.
C)both
D)neither

Question 48

Compared to all liquids,solids,and gases in the universe,plasmas are the most

A)abundant.
B)rare.
C)We don't have enough information at this time.

Question 49

Estimate the mass of air inside an average automobile.

A)2 grams
B)2 kilograms
C)20 kilograms
D)200 kilograms
E)2000 kilograms

Question 50

Suppose you are standing on a weighing scale and all of a sudden the atmosphere vanished.The reading on the scale would

A)increase.
B)decrease.
C)remain the same.
D)quickly reduce to zero.

Question 51

A large block of wood and a smaller block of iron on weighing scales both register the same weight - 1 ton.Taking buoyancy of air into account,which has the greater mass?

A)wood
B)iron
C)Both have the same mass.
D)More information is needed.

Question 52

Use the following figure to answer the question:
It would be easier to pull evacuated Magdeburg hemispheres apart when they are

A)held upside down.
B)at sea level.
C)20 km beneath the ocean surface.
D)20 km above the ocean surface.
E)none of these

Question 53

In a vacuum a marshmallow becomes

A)larger.
B)smaller.
C)flat.
D)a hollow shell.
E)none of the above choices

Question 54

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.

Question 55

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.

Question 56

In a vacuum,an object has no

A)buoyant force.
B)mass.
C)weight.
D)temperature.
E)all of these

Question 57

Glowing plasma is evident in the light from

A)a fluorescent lamp.
B)the aurora borealis (northern lights).
C)an incandescent lamp.
D)Choices A and B are both correct.
E)Choices A and C are both correct.

Question 58

If you release a ball inside a freely falling elevator,it stays in front of you instead of "falling to the floor" because you,the ball,the elevator,and the air in the elevator are all in free fall.If you similarly release a helium-filled balloon,the balloon will

A)also stay in front of you.
B)press against the ceiling.
C)press against the floor.
D)slowly rise.
E)slowly fall.

Question 59

The weight of air in a bathtub (about 1/3 cubic meter)is about the same as the weight of

A)a pea.
B)an egg.
C)a small apple.
D)a pound of butter.
E)a 10-pound sack of potatoes.

Question 60

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.

Question 61

Most of the mass of material that makes up a plasma is

A)electrically neutral.
B)always positively charged.
C)always negatively charged.

Question 62

When a gas is heated and becomes a plasma,its electric charge is usually

A)balanced.
B)negative.
C)positive.
D)non-existent.
E)none of these