Physics Hw questions (Ch. 11-16)

A balloon that weighs 1 N is suspended in air, drifting neither up nor down. (a) How much buoyant force acts on it? (b) What happens if the buoyant force decreases? (c) If the buoyant force increases? (a) 1 N up; (b) it falls; (c) it rises. (a) 1 kg up; (b) it falls; (c) it rises. (a) 1 N up; (b) it rises; (c) it falls. (a) 1 N down; (b) it falls; (c) it rises

(a) 1 N up; (b) it falls; (c) it rises.

The temperature of absolute zero is stated as ___________. 32°C 273K 4 kelvin -273°C

-273°C

If the linear dimensions of an object are doubled, by how much does the surface area increase? By how much does the volume increase? 6 times, 8 times 8 times, 4 times 4 times, 4 times 4 times, 8 times

4 times, 8 times

How does a molecule differ from an atom? Give an example. A molecule is a mixture of atoms: NaCl. A molecule is composed of two or more atoms bonded together: H2O. A molecule is made when two or more nuclei fuse together. A molecule is made only when two or more of the same elements bond together: H2.

A molecule is composed of two or more atoms bonded together: H2O.

How does a plasma differ from a gas? A plasma is much colder than a gas. A plasma is made up of bare atomic nuclei. A plasma is made up of ionized atoms. A plasma is made up of radioactive atoms.

A plasma is made up of ionized atoms.

Distinguish between tension and compression A pulled-apart object is in tension; a pushed-together one is in compression. A high-density object is under tension; a low-density one is under compression. Tension causes things to get shorter and wider; compression causes things to get longer and thinner. In tension, atoms are closer together; in compression, they are further apart.

A pulled-apart object is in tension; a pushed-together one is in compression.

As the text cites, atoms are incredibly tiny, numerous, perpetually moving, and what else? Mainly in the air New in science Ageless Migratory

Ageless

Does the air exert a buoyant force on all objects in air or only on objects such as balloons that are very light for their size? Air has too low a density to exert a buoyant force. Air exerts a buoyant force only on objects less dense than air. Air exerts a buoyant force on all objects. Air exerts a buoyant force only on objects more dense than air.

Air exerts a buoyant force on all objects.

Atmospheric pressure decreases with increasing _________. speed of molecules in the air altitude amounts of sunshine temperature

Altitude

What is a compound? Cite two examples. Atoms of different elements with bonds between them: NaCl and H2 The same types of atoms bonded together: H2 and N2 Atoms pressed together without bonding: air and salt and sand Atoms of different elements with bonds between them: NaCl and H2O

Atoms of different elements with bonds between them: NaCl and H2O

What is a mixture? Cite two examples. Atoms pressed together without bonding: air and salt and sand The same types of atoms bonded together: H2 and N2 Atoms of different elements with bonds between them: NaCl and H2O Atoms pressed together without bonding: H2O and H2

Atoms pressed together without bonding: air and salt and sand

What are the five most common elements in humans? H2O, O2, Ca, N2, and C H, He, C, O, and N C, H, O, N, and Fe C, H, O, N, and Ca

C, H, O, N, and Ca

What kind of attraction pulls electrons close to the atomic nucleus?

Electric

What element has the lightest atoms?

Hydrogen

What is the most abundant element in the known universe?

Hydrogen

Which of the following is an element? Carbon dioxide H2O Hydrogen A supernova

Hydrogen

Where in the atom is most of its mass concentrated? What is this mass composed of?

In the nucleus as protons and neutrons

Does a hot object contain internal energy or does it contain heat? Heat Internal energy Both internal energy and heat Neither internal energy nor heat

Internal Energy

What happens to the air pressure inside a balloon when it is squeezed to half its volume at constant temperature? It doubles. It quadruples. It is cut in half. It remains the same.

It doubles

If you punch holes in the side of a container filled with water, in what direction does the water initially flow outward from the container? It flows straight out, perpendicular to the wall. It drops straight down. The bottom one comes straight out, whereas the upper ones come out at a downward angle. It comes out 45 degrees below horizontal.

It flows straight out, perpendicular to the wall.

Hot sand cools off faster at night than plants and vegetation. This indicates that the specific heat capacity for sand is ___________. likely the same as that of plants unrelated to rate of cooling less than that of plants more than that of plants

Less than plants

Which generally expands more for an equal increase in temperature: solids or liquids? Which generally expands more for an equal increase in temperature: solids or liquids? Liquids generally expand more than solids. Solids and liquids generally expand the same. Solids and liquids generally do not expand when heated. Solids generally expand more than liquids.

Liquids generally expand more than solids.

Why would a water barometer have to be 13.6 times taller than a mercury barometer? The atmospheric pressure on the mercury is 13.6 times greater than the atmospheric pressure on the water. The buoyant force due to the mercury is 13.6 times less than the buoyant force due to the water. Mercury is 13.6 times denser than water. Water is 13.6 times denser than mercury.

Mercury is 13.6 times denser than water.

How does pressure relate to force? Pressure is force per unit area. Pressure is force per unit length. Force is pressure per unit area. Pressure is the same as force.

Pressure is force per unit area.

Is pressure greater or less in regions where streamlines are crowded? Pressure does not depend on streamline spacing. Pressure is greater near the top streamlines and lower near the bottom, regardless of spacing. Pressure is lower where streamlines are closer. Pressure is higher where streamlines are closer.

Pressure is lower where streamlines are closer.

What is Hooke's law? Does it apply to elastic materials or to inelastic materials? Stretch is inversely proportional to force for elastic materials. Stretch is proportional to force for elastic and inelastic materials. Stretch is proportional to force for elastic materials. Stretch is proportional to force for inelastic materials.

Stretch is proportional to force for elastic materials.

What does the atomic number of an element tell you about the element?

The number of protons in its nucleus

A gas will become plasma when it is __________. fused fluoresces electrically charged heated

Electrically charged

Which of the following are negatively charged?

Electrons

According to Hooke's law, if you double the force when stretching a spring, the elongation of the spring is normally __________. twice as much half as much no different, but the same four times as much

twice as much

Part complete If an object suspended by a scale shows a weight of 3 N in air, and 2 N when submerged in water, the buoyant force on the submerged object is __________. more than 3 N 2 N 1 N 3 N

1 N

What are the temperatures for freezing water and boiling water on the Kelvin temperature scale? 0 K, 100 K 32 K, 212 K 373 K, 212 K 273 K, 373 K

273 K, 373 K

If the pressure in a hydraulic press is increased by an additional 10 N/cm2, how much extra load will the output piston support if its cross-sectional area is 50 cm2? 1/5 N 50 N 5N 500 N

500 N

If a 1-kg object stretches a spring by 2 cm, then how much will the spring be stretched when it supports a 3-kg object? (Assume the spring does not reach its elastic limit.) 2 cm 6 cm 3 cm 0.66 cm

6 cm

How is the density of a fish controlled? How is the density of a submarine controlled? A fish changes its weight, whereas a submarine changes its mass. A fish changes its weight, whereas a submarine changes its volume. A fish changes its volume, and a submarine changes its volume, too. A fish changes its volume, whereas a submarine changes its weight.

A fish changes its volume, whereas a submarine changes its weight.

Does a substance that cools off quickly have a high or a low specific heat capacity? A low specific heat capacity A high specific heat capacity Larger objects cool off more quickly, independent of specific heat capacity. Specific heat capacity does not matter.

A low specific heat capacity

When we speak about heat we refer to ___________. temperature energy in transit work transfer of kinetic energy

Energy In Transit

The buoyant force on a floating object is __________. more than the buoyant force than if submerged equal to the object's weight equal to the object's volume less than the object's weight

Equal to the objects weight

What are the temperatures for freezing water on the Celsius and Fahrenheit scales? For boiling water? Freezing: 273°C, 32°F; boiling: 373°C, 212°F Freezing: 0°C, 32°F; boiling: 100°C, 212°F Freezing: 32°C, 0°F; boiling: 100°C, 212°F Freezing: 0°C, 32°F; boiling: 100°C, 273°F

Freezing: 0°C, 32°F; boiling: 100°C, 212°F

In which direction does heat flow spontaneously between hot and cold objects? From high internal energy to low internal energy From low temperature to high temperature From low internal energy to high internal energy From high temperature to low temperature

From high temperature to low temperature

Which warms up fastest when heat is applied: water, iron, or silver? Water warms up faster than iron. Iron warms up faster than silver. Iron warms up faster than silver. Silver warms up faster than water. Water warms up faster than silver. Silver warms up faster than iron. Silver warms up faster than iron. Iron warms up faster than water.

Silver warms up faster than iron. Iron warms up faster than water.

What will these objects do in water: an object denser than water, an object less dense than water, an object that has the same density as water. Float, sink, neither float nor sink Sink, float, sink Float, sink, float Sink, float, neither float nor sink

Sink, float, neither float nor sink

What is the energy source for the motion of gas in the atmosphere? What prevents atmospheric gases from flying off into space? Solar energy, gravity Geothermal energy, gravity Solar energy, clouds Geothermal energy, clouds

Solar energy, gravity

Which of these is most elastic? Air Putty Steel Water

Steel

When you drink liquid through a straw, is it more accurate to say the liquid is pushed up the straw rather than sucked up the straw? What exactly does the pushing? The atmospheric pressure outside the straw pushes the liquid toward the lower pressure in your mouth. The buoyant force of the water causes it to flow into your mouth. Nature abhors the vacuum in your mouth, so the water flows in to fill it. The lower pressure in your mouth sucks the water up the straw.

The atmospheric pressure outside the straw pushes the liquid toward the lower pressure in your mouth.

Part complete How does the buoyant force on a submerged object compare with the weight of the water displaced? The buoyant force is equal to the weight of the water displaced. The buoyant force is less than the weight of the water displaced. Both are zero. The buoyant force is greater than the weight of the water displaced.

The buoyant force is equal to the weight of the water displaced.

What and where is the neutral layer in a beam that supports a load? The layer in the beam where atoms are compressed together most The layer in the beam where atoms are stretched apart most The layer in which there is neither tension nor compression along the middle from end to end The layer in the beam where there is no net electrical charge

The layer in which there is neither tension nor compression along the middle from end to end

What happens to the internal pressure in a fluid flowing in a horizontal pipe when its speed increases? The pressure is independent of the speed. The pressure increases when the speed increases. The pressure decreases when the speed increases. The pressure does not change when the speed increases

The pressure decreases when the speed increases

How does the pressure at the bottom of a 76-cm column of mercury in a barometer compare with the air pressure at the bottom of the atmosphere? The pressure under the mercury is much greater. The pressure of the tall column of air is much greater. The pressures are equal. The pressure from the atmosphere is about 100 kPa, whereas the pressure from the mercury is 13.6 times greater.

The pressure from the atmosphere is about 100 kPa,

What happens to the internal pressure in a fluid flowing in a horizontal pipe when its speed decreases? The pressure is independent of the speed. The pressure decreases when the speed decreases. The speed does not change when the speed decreases. The pressure increases when the speed decreases.

The pressure increases when the speed decreases.

If you swim beneath the surface in saltwater, will the pressure be greater than in fresh water at the same depth? The pressure will be zero. The pressure will be less. The pressure will be the same. The pressure will be greater.

The pressure will be greater.

How does the water pressure 1 m below the surface of a small pond compare with the water pressure 1 m below the surface of a huge lake? The pressure will be the same. The pressure will be greater. The pressure will be zero in both cases. The pressure will be less.

The pressure will be the same.

Why does a bimetallic strip bend with changes in temperature? High temperatures soften the two metals, allowing them to sag under gravity. One metal contracts when heated, whereas the other metal expands. Heating causes the two metals to become a battery that powers the bending. The two metals expand at different rates.

The two metals expand at different rates.

How does the volume of a completely submerged object compare with the volume of water displaced? The volumes of both add to zero. The volume of the submerged object is greater than the volume of displaced water. The volumes are equal. The volume of the submerged object is less than the volume of displaced water.

The volumes are equal.

How is heat similar to and different from internal energy? Heat is not a form of energy, whereas internal energy is. Heat and internal energy are two names for the same thing. They are both forms of energy, but heat flows, whereas internal energy does not. They are both forms of energy, but heat flow is kinetic energy, whereas internal energy is entirely potential energy.

They are both forms of energy, but heat flows, whereas internal energy does not.

When there is faster-moving water between two ships, are the ships sucked together or pushed together? Explain. They are sucked together, because faster flow between the ships decreases the pressure between them. They are both pushed together and sucked together, because faster flow between the ships decreases the pressure between them. They are pushed together, because faster flow between the ships increases the pressure between them. They are pushed together, because faster flow between the ships decreases the pressure between them compared to the exterior pressure.

They are pushed together, because faster flow between the ships decreases the pressure between them compared to the exterior pressure.

Does the buoyant force on a submerged object depend on the volume of the object or on the weight of the object? Both volume and weight Volume Weight Neither volume nor weight

Volume

Why do we say that a spring is elastic? When deformed, it does not return to its original shape. It is made of rubber. It does not obey Hooke's law. When deformed, it returns to its original shape.

When deformed, it returns to its original shape.

Which of the following is stronger per bodyweight? A human A fish An elephant An ant

ant

Water pressure in a lake is greater __________. at the surface at the bottom midway to the bottom at any point, for pressure is the same throughout

at the bottom