physics

You put 1 kg of ice at 0°C together with 1 kg of water at 50°C. What is the final temperature?

0 degrees

You put 1 kg of ice at 0°C together with 1 kg of steam at 100°C. What is the final temperature?

100 degree c

An ideal gas is compressed isothermally to one-third of its initial volume. The resulting pressure will be A) three times as large as the initial value. B) less than three times as large as the initial value. C) more than three times as large as the initial value. D) equal to the initial value. E) impossible to predict on the basis of this data.

A

If, with steady state heat flow established, you double the thickness of a wall built from solid uniform material, the rate of heat loss for a given temperature difference across the thickness will A) become one-half its original value. B) also double. C) become one-fourth its original value. D) become 1/2 of its original value. E) become four times its original value

A

When a gas expands adiabatically, A) the internal (thermal) energy of the gas decreases. B) the internal (thermal) energy of the gas increases. C) it does no work. D) work is done on the gas. E) the temperature of the gas remains constant

A

When a gas expands adiabatically, A) the internal (thermal) energy of the gas decreases. B) the internal (thermal) energy of the gas increases. C) it does no work. D) work is done on the gas. E) the temperature of the gas remains constant.

A

8.0 m3

A balloon originally has a volume of 1.0 m3 when the gas in it is at 20°C and under a pressure of 1.0 atm. As it rises in the earth's atmosphere, its volume expands. What will be its new volume if its final temperature and pressure are -40°C and 0.10 atm?

The helium molecules have the greater speed. The helium molecules have the same average kinetic as the oxygen molecules.

A fixed container holds oxygen and helium gases at the same temperature. Which of the following statements are correct? (There could be more than one correct choice.)

vibrational energy

A form of Kinetic Energy which causes all the molecules of an object or any kind to vibrate.

rotational energy

A form of kinetic energy which occurs when objects spin

Temperature

A measure of the average energy of motion of the particles of a substance.

311°C

A quantity of an ideal gas is kept in a rigid container of constant volume. If the gas is originally at a temperature of 19°C, at what temperature will the pressure of the gas double from its original value?

celsius

A temperature scale in which water freezes at 0 degrees and boils at 100 degrees.

farenheit

A temperature scale in which water freezes at 32 degrees and boils at 212 degrees

phase change

A transition of matter from one state to another

kelvin

A unit of absolute temperature and symbolized as K. Formerly known as degree Kelvin.

A 10-L flask and a 1-L flask each contain two moles of ideal diatomic gas (but not the same gas) at 25°C. Which of the following statements about these gases must be true? (There could be more than one correct choice.) A) The internal (thermal) energy of the gas in both flasks is the same. B) The internal (thermal) energy of the gas in the larger flask is greater than the internal (thermal) energy of the gas in the smaller flask. C) The internal (thermal) energy of the gas in the smaller flask is greater than the internal (thermal) energy of the gas in the larger flask. D) The molecules in the larger flask have the same root-mean-square speed as those in the smaller flask. E) The molecules in the smaller flask have the same average kinetic energy per molecule as those in the larger flask.

A, E

313°C

An ideal gas occupies 6.00 × 102 cm3 at 20°C. At what temperature will it occupy 1.20 × 103 cm3 if the pressure is held constant?

17) If the efficiency of a Carnot engine were to be 100%, the heat sink would have to be A) at absolute zero. B) at 0°C. C) at 100°C. D) infinitely hot.

B

22) When water at 0°C freezes, the entropy of the water A) increases. B) decreases. C) remains constant. D) could either increase or decrease; it depends on other factors.

B

A cyclic process is carried out on an ideal gas such that it returns to its initial state at the end of a cycle, as shown in the pV diagram in the figure. If the process is carried out in a counter-clockwise sense around the enclosed area, as shown on the figure, then the magnitude of the enclosed area represents A) the heat that flows out of the gas. B) the work done on the gas. C) the heat added to the gas. D) the work done by the gas.

B

An ideal gas is compressed isobarically to one-third of its initial volume. The resulting pressure will be A) three times as large as the initial value. B) equal to the initial value. C) more than three times as large as the initial value. D) nine times the initial value. E) impossible to predict on the basis of this data.

B

In a given reversible process, the temperature of an ideal gas is kept constant as the gas is compressed to a smaller volume. Which one of the following statements about the gas is correct? A) The gas must absorb heat from its surroundings. B) The gas must release heat to its surroundings. C) The pressure of the gas also stays constant. D) The process is adiabatic. E) It is impossible to predict on the basis of this data

B

In a given reversible process, the temperature of an ideal gas is kept constant as the gas is compressed to a smaller volume. Which one of the following statements about the gas is correct? A) The gas must absorb heat from its surroundings. B) The gas must release heat to its surroundings. C) The pressure of the gas also stays constant. D) The process is adiabatic. E) It is impossible to predict on the basis of this data.

B

The root-mean-square speed of the molecules of an ideal gas is v. The gas is now slowly compressed to one-half its original volume with no change in temperature. What is the root-mean-square speed of the molecules now?

B) v

0.72 cm

By what length will a slab of concrete that is originally 18 m long contract when the temperature drops from 24°C to -16°C? The coefficient of linear thermal expansion for this concrete is 1.0 × 10-5 K-1.

21) An ideal gas undergoes an isothermal expansion. During this process, its entropy A) decreases. B) remains unchanged. C) increases. D) cannot be predicted from the data given.

C

9) Two metal rods are to be used to conduct heat from a region at 100°C to a region at 0°C as shown in the figure. The rods can be placed in parallel, as shown on the left, or in series, as on the right. When steady state flow is established, the heat conducted in the series arrangement is A) greater than the heat conducted with the rods in parallel. B) the same as the heat conducted with the rods in parallel. C) less than the heat conducted with the rods in parallel.

C

A cyclic process is carried out on an ideal gas such that it returns to its initial state at the end of a cycle, as shown in the pV diagram in the figure. If the process is carried out in a clockwise sense around the enclosed area, as shown on the figure, then the change of internal energy over the full cycle A) is positive. B) is negative. C) is zero. D) cannot be determined from the information given

C

A solid cylindrical bar conducts heat at a rate of 25 W from a hot to a cold reservoir under steady state conditions. If both the length and the diameter of this bar are doubled, the rate at which it will conduct heat between these reservoirs will be A) 200 W B) 100 W C) 50 W D) 25 W E) 12.5 W

C

A sample of an ideal gas is heated and its Kelvin temperature doubles. If the root-mean-square speed of its molecules was originally v, what is the new root-mean-square speed?

C) v squ(2)

1) A cyclic process is carried out on an ideal gas such that it returns to its initial state at the end of a cycle, as shown in the pV diagram in the figure. If the process is carried out in a clockwise sense around the enclosed area, as shown on the figure, then the magnitude of the enclosed area represents A) the heat that flows out of the gas. B) the work done on the gas. C) the heat added to the gas. D) the work done by the gas.

D

15) On a cold day, a piece of metal feels much colder to the touch than a piece of wood. This is due to the difference in which one of the following physical properties of these materials? A) density B) specific heat C) emissivity D) thermal conductivity E) mass

D

18) A Carnot cycle consists of A) two adiabats and two isobars. B) two isobars and two isotherms. C) four isotherms. D) two adiabats and two isotherms. E) four adiabats.

D

3) A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper, with the aluminum and the copper in thermal contact. The specific heat capacity of aluminum is more than double that of copper. Which object experiences the greater temperature change during the time the system takes to reach thermal equilibrium? A) the copper B) the aluminum C) Neither one; both of them experience the same size temperature change. D) It is impossible to tell without knowing the masses. E) It is impossible to tell without knowing the volumes.

D

Which one of the following quantities is the smallest unit of heat energy? A) calorie B) kilocalorie C) Btu D) joule

D

An ideal gas is held in a container of volume V at pressure p. The rms speed of a gas molecule under these conditions is v. If now the volume and pressure are changed to 2V and 2p, the rms speed of a molecule will be

E) 2v

The absolute temperature of a gas is T. In order to double the rms speed of its molecules, what should be the new absolute temperature?

E) 4T

heat

Energy that is transformed as a consequence of temperature differences

140 C°

For the mercury in a thermometer to expand from 4.00 cm3 to 4.10 cm3, what change in temperature is necessary? The mercury has a volume expansion coefficient of 1.80 × 10-4 K-1.

550 m/s

If an ideal gas molecule has a speed of 0.50 km/s at 20°C, what is its speed at 80°C?

celsius to kelvin

K=C+273

A gas is taken through the cycle shown in the pV diagram in the figure. During one cycle, how much work is done by the gas? A) p0V0 B) 2 p0V0 C) 3 p0V0 D) 4 p0V0

LOOK UP IMAGE C

An architect is interested in estimating the rate of heat loss, ΔQ/Δt, through a sheet of insulating material as a function of the thickness of the sheet. Assuming fixed temperatures on the two faces of the sheet and steady state heat flow, which one of the graphs shown in the figure best represents the rate of heat transfer as a function of the thickness of the insulating sheet? A) A B) B C) C D) D E) E

LOOK UP IMAGE C

-321°F

Nitrogen boils at -196°C. What is the corresponding temperature in the Fahrenheit scale?

How much energy is transferred between a piece of toast and an oven when both are at the same temperature of 55 degrees C?

None; there is thermal equilibrium between the toast and the oven...the are both at 55 degrees C.

is the same.

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules,

Two identical cylinders at the same temperature contain the same gas. If B has twice the volume and half the number of moles as A, how does the pressure in B compare with the pressure in A?

PB = 1/4 PA

joule

SI unit of energy

Two containers of equal volume each hold samples of the same ideal gas. Container A has twice as many molecules as container B. If the gas pressure is the same in the two containers, the correct statement regarding the absolute temperatures TA and TB in containers A and B, respectively, is

Ta=1/2 Tb

celsius-fahrenheit temperature conversion

Tf=9/5 Tc + 32.0

the average kinetic energy of its molecules

The absolute temperature of an ideal gas is directly proportional to which of the following quantities?

Effects of Heat Transfer:

The basic effect of heat transfer is that the particles of one substance collide with the particles of another substance. The more energetic substance will typically lose internal energy (i.e. "cool down") while the less energetic substance will gain internal energy (i.e. "heat up").

The First Law of Thermodynamics:

The change in the energy of a system is the amount of energy added to the system minus the energy spent doing work.

5.4 × 10-6 K-1

The coefficient of linear expansion for aluminum is 1.8 × 10-6 K-1. What is its coefficient of volume expansion?

330°C

The coefficient of linear expansion of copper is 17 × 10-6 K-1 and that of steel is 12 × 10-6 K-1. At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm. If they are heated together to a higher temperature, which one of the following quantities is closest to the common temperature at which the steel rod will fit snugly in the copper pipe?

1.2 × 10-7 m3

The density of water at 0°C is 999.84 kg/m3 and at 4°C it is 999.96 kg/m3. A 1.0-L container, full to the brim with water at 4.0°C is placed in the refrigerator. By the time that the temperature of the water reaches 0.0°C, what volume of water has spilled from the container, assuming that the contraction of the container is negligible?

translational energy

The energy of a particle moving in space. It is defined in s of a particle's mass, m, and velocity, v, as (1/2)mv2.

619 m/s

The rms speed of a certain sample of carbon dioxide molecules, with a molecular weight of 44.0 g/mole, is 396 m/s. What is the rms speed of water vapor molecules, with a molecular weight of 18.0 g/mol, at the same temperature as the carbon dioxide?

295k

The temperature in your classroom is closest to

A floor covered with tile feels very cold to your bare feet, but a floor covered with carpet at the same room temperature feels warm to your feet. Why?

Tile is a better conductor of thermal energy therefore the energy transfer happens faster between your feet and the tile.

celsius temperature conversion to fahrenheit formula

To convert to Celsius take Temperature Fahrenheit minus 32 degrees and divide by 1.8.

the two spheres remain of equal size.

Two metal spheres are made of the same material and have the same diameter, but one is solid and the other is hollow. If their temperature is increased by the same amount,

thermodynamic process

What a system undergoes a when there is some sort of energetic change within the system, generally associated with changes in pressure, volume, internal energy (i.e. temperature), or any sort of heat transfer.

A glass of tea has an initial temperature of 8 degrees C. In which situation will the rate of energy transfer be greater, when the airs temperature is 25 degrees C or 35 degrees C?

When the air temperature is 35 degrees C...

1 C° = 1 K

Which two temperature changes are equivalent?

example of translational energy

airplane in flight, carbon dioxide molecule in linear motion

calorimeter

an instrument used to measure changes in thermal energy

Phase changes

are due to potential energy changes.

Two identical cylinders at the same pressure contain the same gas. If A contains three times as much gas as B, which cylinder has the higher temperature?

b will have higher temp

Water has a higher specific heat than sand. Therefore, on the beach at night, breezes would blow:

beach to ocean

A 1 kg block of silver (c = 234 J/kg °C) is heated to 100°C, then dunked in a tub of 1 kg of water (c = 4186 J/kg °C) at 0°C. What is the final equilibrium temperature?

between 0 and 50

Two identical cylinders at the same temperature contain the same gas. If A contains three times as much gas as B, which cylinder has the higher pressure?

cylinder a will have higher pressure

If the Sun's surface temperature falls to half the current surface temperature, by what factor will the radiant energy reaching the Earth change?

decrease by factor of 16

inernal energy

energies associated with atomic motion

heat capacity of a substance

indicates the ease with which a substance heats up. A good thermal conductor would have a low heat capacity, indicating that a small amount of energy causes a large temperature change.

A calorimeter

is a device used to measure the quantity of heat transferred to or from an object

Heat transfer

is a process by which internal energy from one substance transfers to another substance.

A change in temperature

is associated with changes in the average kinetic energy of the particles within the object.

A change in state

is associated with changes in the internal potential energy possessed by the object.

Insulation

is when a low-conducting material is used to prevent heat transfer.

Conduction

is when heat flows through a heated solid.

Radiation

is when heat is transferred through electromagnetic waves, such as from the sun.

Convection

is when heated particles transfer heat to another substance, such as cooking something in boiling water.

Thermal Contact

is when two substances can affect each other's temperature.

Thermal Equilibrium

is when two substances in thermal contact no longer transfer heat.

Which weighs more—a mole of nitrogen (N2) gas or a mole of oxygen (O2) gas?

oxygen

example of vibrational energy

plucked guitar string

The specific heat capacity

refers to the amount of heat required to cause a unit of mass (say a gram or a kilogram) to change its temperature by 1°C

Two objects are made of the same material, but have different masses and temperatures. If the objects are brought into thermal contact, which one will have the greater temperature change?

smallest mass

example of rotational energy

spinning top

Thermal Expansion

takes place when a substance expands in volume as it gains heat. Thermal contraction also exists when heat is lost from a substance.

what is the relationship between temperature and internal energy?

temperature increases as the internal energy increases

Two equal-mass liquids, initially at the same temperature, are heated for the same time over the same stove. You measure the temperatures and find that one liquid has a higher temperature than the other. Which liquid has a higher specific heat?

the cooler one

latent heat

the energy absorbed or released during a change in state

internal energy

the sum of the kinetic and potential energies of all particles in the system

what must be true of two objects if the objects are in a state of thermal equilibrium?

their temperatures are the same

A good thermal insulator

would have a large heat capacity, indicating that much energy transfer is needed for a temperature change.

If you add some heat to a substance, is it possible for the temperature of the substance to remain unchanged?

yes