Physics II Final

heat added to the system

+Q and U increases

Work done by the system

+W and U decreases

heat leaves the system

-Q and U decreases

work done on the system

-W and U increases

isothermal process

1 to 2

An ideal gas undergoes an isothermal process. Which of the following statements are true? (i) No heat is added to or removed from the gas. (ii) The internal energy of the gas does not change. (iii) The average kinetic energy of the molecules does not change.

2 and 3 only

an ideal gas is compressed isothermally to one-third of its initial volume. The resulting pressure will be

3 times as large as the initial value

When using the ideal gas law, which of the following rules must be obeyed?

Always use temperature in kelvins and absolute pressure.

A thermally isolated system consists of a hot piece of aluminum and a cold piece of copper. The aluminum and the copper are in thermal contact. The specific heat of aluminum is more than double that of copper. Which object experiences the greater amount of heat transfer during the time it takes the system to reach thermal equilibrium?

Both experience the same magnitude of heat transfer.

Which temperature scale does NOT have negative values?

Kelvin temp scale

The linear expansion of a material depends on which of the following?

Length of the material, type of material, the change in temperature of the material

Isobaric process

P is constant

isobaric graph

P vs V graph where P is kept constant

isochoric/isovolumetric graph

P vs V graph where V is kept constant

When the 1st law of thermodynamics ΔU = Q-W is applied to an ideal gas that is taken through an adiabatic process,

Q = 0

an ideal gas undergoes an isothermal expansion from state A to state B. In this process,

Q > 0 ΔU = 0 W > 0

An ideal gas undergoes an isothermal expansion from state A to state B. In this process,

Q>0 ΔU=0 W>0

Rod AA has twice the diameter of rod BB, but both are made of iron and have the same initial length. Both rods are now subjected to the same change in temperature (but remain solid). How would the change in the rods' lengths compare?

Rod A = Rod B

isothermal process

T is constant

isothermal compression graph

T vs V graph where T is kept constant

In a mixture of the gases oxygen and helium, which statement is valid?

The helium atoms will be moving faster than the oxygen molecules, on average.

A flat metal washer is heated. As the washer's temperature increases, what happens to the hole in the center?

The hole in the center of the washer will expand.

A steel plate has a hole in it with a diameter of exactly 1.0 cm when the plate is at a temperature of 20C. A steel ring has an inner diameter of exactly 1.0 cm at 20C. Both the plate and the ring are heated to 100C. What statement is true?

The hole in the plate and the opening in the ring get larger.

Which of the following does the internal energy of an ideal gas depend upon?

The internal energy depends upon its temperature.

The temperature of an ideal gas increases. What is true?

The pressure, the volume, or both may increase

If the pressure acting on a given sample of an ideal gas at constant temperature is tripled, what happens to the volume of the gas?

The volume is reduced to one-third of its original value.

Isovolumetric process

V is constant

Isochoric process

V1 up to P1

isobaric process

V2 to V1

When the 1st law of thermodynamics ΔU = Q-W is applied to an ideal gas that is taken through an isochoric process,

W = 0

It has been a hot summer, so when you arrive at a lake, you decide to go for a swim even though it is nighttime. The water is cold! The next day, you go swimming again during the hottest part of the day, and even though the air is warmer the water is still almost as cold. Why?

Water has a high specific heat.

As heat is added to water, is it possible for the temperature measured by a thermometer in the water to remain constant?

Yes, the water could be changing phase.

A gas is quickly compressed in an isolated environment. During the event, the gas exchanged no heat with its surroundings. This process is

adiabatic

Which is possible: converting (i) 100 J of work entirely into 100 J of heat, (ii) 100 J of heat entirely into 100 J of work?

both are possible

An ideal gas undergoes an adiabatic expansion, a process in which no heat flows into or out of the gas. As a result,

both the temperature and pressure of the gas decrease.

Radiation is emitted

by any object not at 0 K

By which primary heat transfer mechanism does one end of a steel rod become hot when the other end is placed in a flame?

conduction

A typical thermos bottle has a thin vacuum space between the shiny inner flask (which holds a liquiand the shiny protective outer flask, often stainless steel. The vacuum space is excellent at preventing

conduction and convection.

Which physical law underlies the first law of thermodynamics?

conservation of energy

What is the primary mechanism by which heat is transferred through a pot of soup being heated on the stove?

convection

in compression, volume

decreases. Work is done ON the system (+W)

For objects at thermal equilibrium, which of the following is true?

each is at the same temperature

an ideal gas is compressed isobarically to 1/3 of its initial volume. The resulting pressure will be

equal to the initial value

The quantity Q is the __________ that is added to the system

heat

When you put an ice cube in a glass of warm tea, which of the following happens?

heat flows from the tea to the ice cube

Which of the following happens when a material undergoes a phase change?

heat flows into or out of the material

One mole of an ideal gas in a sealed rigid container is initially at a temperature of 100C. The temperature is then increased to 200C. The pressure in the gas...

increases by about 25%

A gas is compressed to 1/2 of its original volume during an isothermal process. The final pressure of the gas

increases to twice its original value

in expansion, volume

increases. Work is done BY the system (-W)

The quantity ΔU in the first law of thermodynamics is the change in the __________ of the system

internal energy

Adiabatic process

no heat flow into or out of the system, so Q is 0

If heat is added to a system (Q>0) and no change in internal energy of the system occurs (ΔU=0), then the system must do __________ work on the outside world.

positive

By which primary heat transfer mechanism does the Sun warm Earth?

radiation

in an isothermal process, there is no change in

temperature

heat is

the amount of energy transferred between objects as a result of a difference in temperature.

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?

the gas must release heat to its surroundings

when a gas expands adiabatically,

the internal (thermal) energy of the gas decreases.

An ideal gas is in a sealed rigid container. The average kinetic energy of the gas molecules depends most on

the temperature of the gas

Both beakers AA and BB in the figure contain a mixture of ice and water at equilibrium. Which beaker is the coldest, or are they equal in temperature?

they are equal

The rms speed of the molecules of an ideal gas

will increase as the temperature of a gas increases

The quantity W in the first law refers to the __________.

work done by the system

In an isobaric compression of an ideal gas,

work is done on the gas

When the 1st law of thermodynamics ΔU = Q-W is applied to an ideal gas that is taken through an isothermal process,

ΔU is 0