The amount of heat necessary to raise the temperature of 1 gram of water by 1 degree C is reffered to as the
B) calorie
A cup of water is scooped up from a swimming pool of water. Compare the temperature T and the internal energy of U of the water, in both the cup and the swimming pool.
A) Tpool is equal to Tcup, and Upool is greater than Ucup.
It is a well-known fact that water has a higher specific heat capacity than iron. Now, consider equal masses of water and iron that are initially in thermal equilibrium. The same amount of heat, 30 calories, is added to each. Which statement is true?
A) They are no longer in thermal equilibrium; the iron is warmer.
In a cloud formation, water vapor condenses into water droplets which get bigger and bigger until it rains. This will cause the temperature of the air in the clouds to
D) increase
The process whereby heat flows by means of molecular collisions is referred to as
C) conduction
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 property?
C) thermal conductivity
Phase changes occur
B) as the temperature remains the same
If heat is added to a pure substance at a steady rate,
D) More than one of the above is true.
Also, ask questions whenever you're not sure.
Convection can occur
C) only in liquids and gases
16.5 kcal of heat is equivalent to how much work?
A) 69100J
16.5 kcal = 16500 cal; W = KE, KE = J, 16500x4.18 = 68970 which I guess is close to 69100?
When the first law of thermodynamics, Q = U + W, is applied to an ideal gas that is taken through an isothermal process,
B) U = 0
Is it possible to transfer heat from a cold reservoir to a hot reservoir?
B) Yes, but work will have to be done.
The efficiency of a heat engine is defined as the ratio of
C) the work it does to the heat input at the high temperature
(eff = W/Qh)
During an isothermal process, 5.0J of heat is removed from an ideal gas. What is the change in internal energy?
C) zero
(isothermal, U = 0, Q = -W, etc)
A gas is taken through the cycle illustrated (rectangle, P-2P x V-4V). During one cycle, how much work is done by an engine operating on this cycle?
D) 3PV
(W is area inside box, so 1Px3V=3PV)
200J of work is done in compressing a gas adiabatically. What is the change in internal energy of the gas?
A) 200J
(adiabatic, Q = 0, U = W, etc)
In an isochoric process, the internal energy of a system decreases by 50J. What is the work done?
B) zero
(isochoric, vertical line, W = 0)
A Carnot cycle consists of
A) two adiabats and two isotherms
If the theoretical efficiency of a Carnot engine is to be 100%, the heat sink must be
C) at absolute zero
The second law of thermodynamics leads us to conclude that
C) disorder in the universe is increasing with the passage of time.
In an isochoric process going upwards, what are the values of W, Q, and U in terms of pos, neg, or zero?
W = 0, Q = +, U = +
In an isothermal process going right, what are the values of W, Q, and U in terms of pos, neg, or zero?
W = -, Q = +, U = 0
In an isobaric process going left, what are the values of W, Q, and U in terms of pos, neg, or zero?
W = +, Q = -, U = -
Pressure is
C) proportional to force and inversely proportional to area
Consider three drinking glasses. All three have the same area base, and all three are filled to the same depth with water. Glass A is cylindrical. Glass B is wider at the top than the bottom, and so holds more water than A. Glass C is narrower at the top than at the bottom, and so holds less water than A. Which glass has the greatest liquid pressure at the bottom?
A) All three have equal pressure.
(The only factor in pressure is h, all which are the same in this example.)
When atmospheric pressure changes, what happens to the absolute pressure at the bottom of a pool?
C) It increases by the same amount.
(Atm pressure is only added to gauge pressure for absolute.)
An ideal fluid flows at 12m/s in a horizontal pipe. If the pipe widens to twice its original radius, what is the flow speed in the wider section?
A) 6.0m/s
(A1V1=A2V2)
As a rock sinks deeper and deeper into water of a constant density, what happens to the buoyant force on it?
A) It remains constant.
(Fb = pVg, V is constant as long as it is continually completely submerged)
A steel ball sinks in water but floats in a pool of mercury. Where is the buoyant force on the ball greater?
B) floating on the mercury
(mg is constant, so Fb must be greater in mercury to make it float while it sinks in water)
A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub?
C) It does not change.
Which of the following is associated with the law of conservation of energy in fluids?
D) Bernoulli's principle
(P1 + pgy1 + (1/2)pv1^2 = P2 + pgy2 + (1/2)pv2^2)
Water flows through a pipe. The diameter of the pipe at point B is larger than at point A. Where is the water pressure greatest?
B) point B
What is the gauge pressure at a location 15.0m below the surface of the sea? (The density of seawater is 1.03/10^3 kg/m^3).
C) 1.51x10^5 N/m^2
(P=pgh)
What is the tension on a cord pulling a 3.0cm x 4.0cm x 5.0cm of a gold bar (pau = 19x10^3 kg/m^3) from a sunken ship with a constant acceleration of 0.8m/s^2? (psw=1.03x10^3 kg/m^3)
p=m/v, convert cm -> m, m=1.14; Fb=pvg, Fb=0.61; EF=ma, so Ft+Fb-Fg=ma, Ft=mg+ma-Fb, Ft=11.48
A bimetallic strip, consisting of metal G on the top and metal H on the bottom, is rigidly attached to a wall at the left. The coefficient of linear thermal expansion for metal G is greater than that of metal H. If the strip is uniformly heated, it will
C) curve downward
Consider a flat steel plate with a hole through its center. When the plate's temperature is increased, the hole will
C) always expand
A steel bride is 100m long at -20C in winter. What is the change in length when the temperature rises to 40C in the summer? (The average coefficient of linear expansion of steel is 11x10^-6)
B) 0.66m
(changeinL = (coeff)(orig L)(changeinT))
A container of an ideal gas at 1atm is compressed to one-third its volume, with the temperature held constant. What is its final pressure?
B) 3atm
(P1V1=P2V2)
A container holds N molecules of an ideal gas at a given temperature. If the number of molecules in the container is increased to 2N with no change in temperature or volume, the pressure in the container
A) doubles
(PV=NkT)
According to the idea gas law, PV = constant for a given temperature. As a result, an increase in volume corresponds to a decrease in pressure. This happens because the molecules
C) strike the container wall less often
The average molecular kinetic energy of a gas can be determined by knowing only
C) the temperature of the gas.
Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen, compared to hydrogen
C) is the same
A container is filled with a mixture of helium and oxygen gases. A thermometer in the container indicates that the temperature is 22C. Which gas molecules have the greater average kinetic energy?
D) It is the same for both because the temperatures are the same.
In order to double the average speed of the molecules in a given sample of gas, the temperature (measured in Kelvin) mus
C) increase by a factor of square root two of its original value
The temperature of an ideal gas increase from 2C to 4C while remaining at constant pressure. What happens to the volume of the gas?
A) It increases slightly
On a temperature vs. time graph for a substance being heated uniformly, what are the formulas for Q?
