PY 131 Conceptual Academy Chapter 14 Quizzes

It is easier to move through air than through water because air molecules

are spaced farther apart.

Without solar energy our atmosphere would

transform to a solid.

The Moon has little to no atmosphere because

its gravity is weak.

Atmospheric pressure is due mainly to

the weight of the atmosphere.

How much air pressure was in the hemispheres used in the Magdeburg demonstration many years ago?

Very low, a near vacuum

What does the kid sister in the swimming pool illustrate?

Air has weight

When you squeeze a balloon

it becomes more dense, volume decreases, and pressure increases.

Boyle's law tells us that when pressure in a confined volume of gas is increased

volume decreases proportionally.

Squeeze molecules in a gas together and the gas becomes

more dense

Archimede's principle applies to

liquids as well as gases, both of which are fluids.

If a balloon is lighter than the air it displaces, the balloon will

rise

A balloon in air will stop rising when

its density matches the density of the surrounding air.

Where the speed of a fluid increases,

internal pressure in the fluid decreases.

When a fluid flows into a constricted region, the speed of the fluid

increases.

Air bubbles in a stream of water become smaller when the speed of the stream

decreases.

How many protons in a neon atom?

ten

Atmospheric pressure decreases with increasing

altitude.

Atmospheric pressure is mainly due to the

weight of air.

When a party balloon is compressed to one-third its volume, gas pressure in the balloon

triple

A 1-kg balloon at equilibrium in the air is buoyed up with a force of

10 newtons

A helium-filled balloon will reach its maximum altitude when

its weight equals the weight of displaced air.

When the speed of a fluid increases, internal pressure in the fluid

decreases

Air pressure over the surface of a bird's wings decreases when

air speed increases there.

Pressure in a fluid decreases when its streamlines

are crowded.

A gas will become plasma when it is

electrically charged

You have two barometers filled with liquid mercury, but one with a cross-sectional area two times that of the other. Neglecting surface tension, mercury in the smaller tube will rise

the same height as in the larger tube.

While a water barometer extends to 10.3 meters, at the same atmospheric pressure a less-dense alcohol barometer would extend to

more than 10.3 m

How does the bouyant force on a 2-liter helium balloon compare to a nearby 2-liter jug of water?

The buoyant force on the balloon and the jug of water are the same.

An airliner flying at an 8-km altitude has about what percentage of the atmosphere beneath it?

more than 50 percent

What immediately happens to a marshmallow when placed in a vacuum?

It becomes larger.

Why don't molecules of the atmosphere fly off into outer space?

Because of Earth gravitation.

How does a plasma differ from a gas?

A plasma is electrically conducting.

What law or principle best explains the flight of a blimp?

Archimedes' principle.

What happens to the density of a gas when its container is reduced to half its volume?

The density doubles.

What happens to a bubble of air when it rises from the bottom of a lake?

It becomes larger as it rises.

What concept underlies the functioning of a drinking straw?

atmospheric pressure

What is the buoyant force on a 2-ton blimp hovering in the air?

2 tons (buoyant force=weight)

Two side-by-side parallel ships are drawn together when moving in

either the same or opposite directions.

A scale shows a block of wood and a smaller block of gold to have the same weight of 300 pounds. Considering the effect of buoyant force, which has more mass?

The wood has more mass. (takes up more space)

In any sized room, what does air possess?

All of these (mass, weight, energy)

Heating a gas to a plasma phase results in what kind of charge?

Balanced charges.

A drinking glass filled with air is inverted into water. What happens to the buoyant force on the glass as it is pushed deeper?

They buoyant force decreases.

What does an object not have when in a vacuum?

Buoyant force.

What happens to the size of a weather balloon as it rises to high altitudes?

Its density decreases.

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

considerably less.

A helium balloon floats freely in a car driving with closed windows. What happens to the balloon when the car turns left?

The balloon moves to the left.

What is the approximate weight of air within an empty bathtub of volume one-half cubic-meter?

The air weighs about that of a pound of butter.

How can you make a 5-liter aluminum can float in the air?

A can will not float in air unless the displaced air weighs more than the can and its contents.

What mostly causes atmospheric pressure?

The weight of the atmosphere.

What happens to the air pressure as a wind blows over a hill?

It decreases.

Theoretically, what is the maximum height of water operated by a vacuum pump?

Only 10.3 m

How tall is a column of liquid mercury that has the same mass of air that extends from sea level to the top of the atmosphere?

About 3/4 meter.

What part of our solar system consists primarily of plasma?

The Sun.

How does a suction cup stick to a wall?

It is pushed to the wall by the atmosphere.

Of all forms of ordinary matter, how common is the plasma phase in this universe?

Abundant.

What happens to the size of a weather balloon as it drops from a super high altitude?

It experienes a decrease in volume.

What most energizes the molecules in the atmosphere?

Solar power.

What law or principle best explains the flight of an airplane?

Bernoulli's principle.

Consider a one-square-meter column of air extending from sea level to outer space. What is the weight of air within this column?

101,000 newtons

If there were no atmosphere, your weight as measured on a typical bathroom scale would be

greater

What happens to the internal pressure within a fluid as it gains speed?

There is less internal pressure.

Two very long identical tubes are held vertically. One is filled with 0.760 m of liquid mercury while the other is filled with 10.3 m of water. In this case, both liquids have the same

weights

What type of electric generator employs the plasma phase?

**MHD generators.**

What is the electric charge of most material within a plasma?

Electrically neutral.

On a windy day, why does an umbrella tend to move upward?

Air pressure is reduced over the curved top surface.

While in an elevator that undergoes free-fall, you let go of a helium balloon. What happens to the balloon?

The balloon stays in front of you.

Consider a one-square-centimeter column of air extending from sea level to outer space. What is the mass of air within this column?

1 kg (1 kg per 1 cm squared)

By mass, about how much air is inside an averaged-size car?

2 kilograms

In what phase is mercury within a lit fluorescent lamp?

A plasma phase.

What happens to the density of a man holding his breath as he swims deeper?

It increases

Why does a snorkel more than 1 meter long not allow the snorkeler to dive more than 1 meter deep?

Air at the surface will not freely enter the higher-pressure region in the compressed lungs.

What happens to the pressure of a gas when its temperature remains the same while its container is reduced to half its volume?

The pressure doubles.

What happens to the buoyant force on a free-to-expand balloon filled with helium gas as it rises within the atmosphere? (Assume no change due to temperature.)

The buoyant force remains nearly the same for a long way.

How tall is a column of water having the same mass as a same-sized column of air extending from sea level to the top of the atmosphere?

10\.3 meters

Identify the buoyant force that acts on a balloon?

\n **The weight of air it displaces.**

A drinking glass filled with air is inverted into water. How deep must you push the glass so that the volume of air within the glass is one-half the volume of the glass?

10\.3 m

Air is blown between two Ping-Pong balls 1 cm apart and hanging from strings. What happens next?

\n **The balls move toward each other.**

Identify places where you can witness the plasma phase.

A fluorescent lamp and the aurora borealis.

What distinguishes a plasma from a gas?

Electrical conduction.

What happens to a rubber balloon filled with helium as it rises in the atmosphere?

The size becomes bigger.

Which of these is in a plasma phase?

A torch flame

When will a helium-filled rubber balloon cease to rise in the atmosphere? Assume it doesn't pop.

Until the balloon and surrounding air have equal densities.

Why does a shower curtain move inward when the shower is turned on?

Pressure of a moving fluid.

Two Magdeburg hemispheres are held together after being evacuated of air. It would be easier to pull them apart if they were

\n **20 km above the ocean surface.**

Wind blowing strong from the east breaks a south-facing window. Where will most of the broken glass fall?

Outside the house.

How does the air pressure in a fully-inflated party balloon compare with the surrounding air pressure?

The pressure is greater than air pressure outside the balloon.

What is the predominant phase of ordinary matter within the universe?

plasma state