The first law of thermodynamics is ΔU = Q + W. For each of the following cases, state whether the internal energy of an ideal gas increases, decreases, or remains constant: (a) No energy is transferred to the gas as it expands to twice its original volume. (b) The gas volume is held constant while energy Q is removed. (c) The gas volume is held constant and no energy is transferred to or from the gas. (d) The gas temperature increases.
> The bottom of a copper kettle has a 10.0-cm radius and is 2.00 mm thick. The temperature of the outside surface is 102°C, and the water inside the kettle is boiling at 1 atm of pressure. Find the rate at which energy is being transferred through the bott
> The filament of a 75-W light bulb is at a temperature of 3300 K. Assuming the filament has an emissivity e = 1.0, find its surface area.
> Measurements on two stars indicate that Star X has a surface temperature of 5727°C and Star Y has a surface temperature of 11727°C. If both stars have the same radius, what is the ratio of the luminosity (total power output) of Star Y to the luminosity o
> A granite ball of radius 2.00 m and emissivity 0.450 is heated to 135°C. (a) Convert the given temperature to Kelvin. (b) What is the surface area of the ball? (c) If the ambient temperature is 25.0°C, what net power does the ball radiate?
> A rectangular glass window pane on a house has a width of 1.0 m, a height of 2.0 m, and a thickness of 0.40 cm. Find the energy transferred through the window by conduction in 12 hours on a day when the inside temperature of the house is 22°C and the out
> A Styrofoam box has a surface area of 0.80 m2 and a wall thickness of 2.0 cm. The temperature of the inner surface is 5.0°C, and the outside temperature is 25°C. If it takes 8.0 h for 5.0 kg of ice to melt in the container, determine the thermal conducti
> A person’s basal metabolic rate (BMR) is the rate at which energy is expended while resting in a neutrally temperate environment. A typical BMR is 7.00 x 106 J/day. Convert this BMR to units of (a) Watts and (b) Kilocalories (or Calories) per hour. (c) S
> A copper rod and an aluminum rod of equal diameter are joined end to end in good thermal contact. The temperature of the free end of the copper rod is held constant at 100.°C and that of the far end of the aluminum rod is held at 0°C. If the copper rod i
> A 12 - V battery is connected across a device with variable resistance. As the resistance of the device increases, determine whether the following quantities increase, decrease, or remain unchanged. Indicate your answers with I, D, or U, respectively. (a
> A thermopane window consists of two glass panes, each 0.50 cm thick, with a 1.0-cm-thick sealed layer of air in between. (a) If the inside surface temperature is 23°C and the outside surface temperature is 0.0°C, determine the rate of energy transfer thr
> Consider two cooking pots of the same dimensions, each containing the same amount of water at the same initial temperature. The bottom of the first pot is made of copper, while the bottom of the second pot is made of aluminum. Both pots are placed on a h
> The average thermal conductivity of the walls (including windows) and roof of a house in Figure P11.46 is 4.8 x 10-4 kW/m · °C, and their average thickness is 21.0 cm. The house is heated with natural gas, with a heat of combusti
> A steam pipe is covered with 1.50-cm-thick insulating material of thermal conductivity 0.200 cal/cm · °C · s. How much energy is lost every second when the steam is at 200.°C and the surrounding air is at 20.0 °C? The pipe has a circumference of 800. cm
> The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m · K and 0.020 W/m · K, respectively, while other tissues inside the body have conductivities of about 0.50 W/m · K. Assume that between the core
> A pond with a flat bottom has a surface area of 820 m2 and a depth of 2.0 m. On a warm day, the surface water is at a temperature of 25°C, while the bottom of the pond is at 12°C. Find the rate at which energy is transferred by conduction from the surfac
> A glass windowpane in a home is 0.62 cm thick and has dimensions of 1.0 m x 2.0 m. On a certain day, the indoor temperature is 25°C and the outdoor temperature is 0°C. (a) What is the rate at which energy is transferred by heat through the glass? (b) How
> The plates of a capacitor are connected to a battery. (a) What happens to the charge on the plates if the connecting wires are removed from the battery? (b) What happens to the charge if the wires are removed from the battery and connected to each other?
> If you are given three different capacitors C1, C2, and C3, how many different combinations of capacitance can you produce, using all capacitors in your circuits?
> Consider point A in Figure CQ15.8 located an arbitrary distance from two point charges in otherwise empty space. (a) Is it possible for an electric field to exist at point A in empty space? (b) Does charge exist at this point? (c) Does a force exist at t
> If a suspended object A is attracted to a charged object B, can we conclude that A is charged? Explain.
> A 3.00-g lead bullet at 30.0°C is fired at a speed of 2.40 x 102 m/s into a large, fixed block of ice at 0°C, in which it becomes embedded. (a) Describe the energy transformations that occur as the bullet is cooled. What is the final temperature of the b
> Two uncharged, conducting spheres are separated by a distance d. When charge -Q is moved from sphere A to sphere B, the Coulomb force between them has magnitude F0. (a) Is the Coulomb force attractive or repulsive? (b) If an additional charge -Q is moved
> The fundamental charge is e = 1.60 x 10-19 C. Identify whether each of the following statements is true or false. (a) It’s possible to transfer electric charge to an object so that its net electric charge is 7.5 times the fundamental electric charge, e.
> A student who grew up in a tropical country and is studying in the United States may have no experience with static electricity sparks and shocks until his or her first American winter. Explain.
> A spherical surface surrounds a point charge q. Describe what happens to the total flux through the surface if (a) The charge is tripled, (b) The volume of the sphere is doubled, (c) The surface is changed to a cube, (d) The charge is moved to another lo
> A bat flying at 5.00 m/s is chasing an insect flying in the same direction. If the bat emits a 40.0-kHz chirp and receives back an echo at 40.4 kHz, (a) What is the speed of the insect? (b) Will the bat be able to catch the insect? Explain.
> Why should a ground wire be connected to the metal support rod for a television antenna?
> In fair weather, there is an electric field at the surface of the Earth, pointing down into the ground. What is the sign of the electric charge on the ground in this situation?
> Each of the following statements is related to standing waves on a string. Choose the words that make each statement correct. (i) The harmonic number is equal to the number of [(a) nodes; (b) antinodes]. (ii) The distance from a node to its adjacent anti
> Why does a vibrating guitar string sound louder when placed on the instrument than it would if allowed to vibrate in the air while off the instrument?
> Explain how the distance to a lightning bolt (Fig. CQ14.4) can be determined by counting the seconds between the flash and the sound of thunder. Fig CQ14.4:
> The excess internal energy of metabolism is exhausted through a variety of channels, such as through radiation and evaporation of perspiration. Consider another pathway for energy loss: moisture in exhaled breath. Suppose you breathe out 22.0 breaths per
> When dealing with sound intensities and decibel levels, a convenient approximation (accurate to 2 significant figures) is: For every doubling of the intensity, the decibel level increases by 3.0. Suppose the sound level at some location is 85 dB. Find th
> A soft drink bottle resonates as air is blown across its top. What happens to the resonant frequency as the level of fluid in the bottle decreases?
> A block connected to a horizontal spring is in simple harmonic motion on a level, frictionless surface, oscillating with amplitude A around x = 0. Identify whether each of the following statements is true or false: (a) If x = (A then |v|=|vmax| and |a|=|
> If a spring is cut in half, what happens to its spring constant?
> If the spring constant shown in Figure CQ13.3 is doubled to 2k0, determine (a) The ratio of the new force to the original force, Fn/F0, and (b) The ratio of the new to the original elastic potential energy, PEsn/PEs0. Figure CQ13.3:
> If an object – spring system is hung vertically and set into oscillation, why does the motion eventually stop?
> Identify each of the following waves as either transverse or longitudinal: (a) The waves on a plucked guitar string. (b) The sound waves produced by a vibrating guitar string. (c) The waves on a spring with its end pumped back and forth along the spring’
> If you stretch a rubber hose and pluck it, you can observe a pulse traveling up and down the hose. What happens to the speed of the pulse if you stretch the hose more tightly? What happens to the speed if you fill the hose with water?
> If a grandfather clock were running slow, how could we adjust the length of the pendulum to correct the time?
> A thermodynamic process occurs in which the entropy of a system changes by -6 J/K. According to the second law of thermodynamics, what can you conclude about the entropy change of the environment? (a) It must be +6 J/K or less. (b) It must be equal to 6
> A 55-kg student eats a 540-Calorie (540 kcal) jelly doughnut for breakfast. (a) How many joules of energy are the equivalent of one jelly doughnut? (b) How many stairs must the student climb to perform an amount of mechanical work equivalent to the food
> Power P0 = I0 ΔV0 is delivered to a resistor of resistance R0. If the resistance is doubled (Rnew = 2R0) while the voltage is adjusted such that the current is constant, what are the ratios (a) Pnew/P0 and (b) ΔVnew/ΔV0? If, instead, the resistance is he
> Star A has twice the radius and twice the absolute temperature of star B. What is the ratio of the power output of star A to that of star B? The emissivity of both stars can be assumed to be 1. (a) 4 (b) 8 (c) 16 (d) 32 (e) 64
> What is wrong with the following statement: “Given any two bodies, the one with the higher temperature contains more heat.”
> On a very hot day, it’s possible to cook an egg on the hood of a car. Would you select a black car or a white car on which to cook your egg? Why?
> Objects A and B with TA > TB are placed in thermal contact and come to equilibrium. (a) For which object does the entropy increase? (b) For which object does the entropy decrease? (c) Which object has the greater magnitude of entropy change?
> Objects A and B have the same size and shape with emissivities eA and eB and temperatures TA and TB, respectively. (a) If eA = eB and TB = 4TA, what is the ratio PB /PA of their radiated powers? (b) If, instead, they radiate the same power and eA = 4eB,
> In a calorimetry experiment, three samples A, B, and C with TA > TB > TC are placed in thermal contact. When the samples have reached thermal equilibrium at a common temperature T, which one of the following must be true? (a) QA > QB > QC (b) QA < 0, QB
> A heat engine does work Weng while absorbing energy Qh from the hot reservoir and expelling energy Qc to the cold reservoir. Which one of the following is impossible? (a) |Qh| > |Qc| > Weng (b) |Qh| > Weng > |Qc| (c) |Qh| > Weng = |Qc| (d) Weng > |Qh| (e
> The U.S. penny is now made of copper-coated zinc. Can a calorimetric experiment be devised to test for the metal content in a collection of pennies? If so, describe the procedure.
> An ideal gas undergoes an adiabatic process so that no energy enters or leaves the gas by heat. Which one of the following statements is true? (a) Because no energy is added by heat, the temperature cannot change. (b) The temperature increases if the gas
> Steam at 100.°C is added to ice at 0°C. (a) Find the amount of ice melted and the final temperature when the mass of steam is 10. g and the mass of ice is 50. g. (b) Repeat with steam of mass 1.0 g and ice of mass 50. g.
> Different amounts of thermal energy are added to each of three isolated samples A, B, and C of lead. If the energy transfers are ordered as QB > QC > QA and each sample undergoes the same temperature change, which sample has the largest mass?
> Clearly distinguish among temperature, heat, and internal energy.
> Equal masses of substance A at 10.0°C and substance B at 90.0°C are placed in a well-insulated container of negligible mass and allowed to come to equilibrium. If the equilibrium temperature is 75.0°C, which substance has the larger specific heat? (a) Su
> Which one of the following statements is true? (a) The path on a PV diagram always goes from the smaller volume to the larger volume. (b) The path on a PV diagram always goes from the smaller pressure to the larger pressure. (c) The area under the path o
> On a clear, cold night, why does frost tend to form on the tops, rather than the sides, of mailboxes and cars?
> For each of the following temperatures, find the equivalent temperature on the indicated scale: (a) -273.15°C on the Fahrenheit scale, (b) 98.6°F on the Celsius scale, and (c) 1.00 x 102 K on the Fahrenheit scale.
> Calculate the slopes for the A, C, and E portions of Figure 11.3. Rank the slopes from least to greatest and explain what your ranking means. (a) A, C, E (b) C, A, E (c) E, A, C (d) E, C, A Figure 11.3:
> Suppose you have 1 kg each of iron, glass, and water, and all three samples are at 10°C. (a) Rank the samples from lowest to highest temperature after 100 J of energy is added to each by heat. (b) Rank them from least to greatest amount of energy transfe
> The switch is closed in Figure 18.20. After a long time compared with the time constant of the circuit, what will the current be in the 2 - Ω resistor? (a) 4 A (b) 3 A (c) 2 A (d) 1 A (e) More information is needed. Figure 18.20:
> If the light-bulbs in Quick Quiz 18.7 are connected one by one in series instead of in parallel, what happens to (a) The brightness of the light-bulbs? (b) The individual currents in the light-bulbs? (c) The power delivered by the battery? (d) The lifeti
> A 60.0-kg runner expends 3.00 x 102 W of power while running a marathon. Assuming 10.0% of the energy is delivered to the muscle tissue and that the excess energy is removed from the body primarily by sweating, determine the volume of bodily fluid (assum
> Suppose you have three identical light-bulbs, some wire, and a battery. You connect one light-bulb to the battery and take note of its brightness. You add a second light-bulb, connecting it in parallel with the previous light-bulbs, and again take note o
> When the switch is open in Figure 18.8, power Po is delivered to the resistor R1. When the switch is closed, which of the following is true about the power Pc delivered to R1? (Neglect the internal resistance of the battery.) (a) Pc (b) Pc = Po (c) Pc &g
> In Figure 18.8, the current is measured with the ammeter on the right side of the circuit diagram. When the switch is closed, does the reading on the ammeter (a) Increase, (b) Decrease, or (c) Remain the same? Figure 18.8:
> The circuit in Figure 18.5 consists of two resistors, a switch, an ammeter, and a battery. When the switch is closed, power Pc is delivered to resistor R1. When the switch is opened, which of the following statements is true about the power Po delivered
> In Figure 18.5, the current is measured with the ammeter at the bottom of the circuit. When the switch is opened, does the reading on the ammeter (a) Increase, (b) Decrease, or (c) Not change? Figure 18.5:
> Why does a battery get warm while in use?
> True or False: While discharging, the terminal voltage of a battery can never be greater than the emf of the battery.
> Two resistors, A and B, are connected in a series circuit with a battery. The resistance of A is twice that of B. Which resistor dissipates more power? (a) Resistor A does. (b) Resistor B does. (c) More information is needed.
> For the two resistors shown in Figure 17.12, rank the currents at points a through f from largest to smallest. (a) Ia = Ib > Ie = If > Ic = Id (b) Ia = Ib > Ic = Id > Ie = If (c) Ie = If > Ic = Id > Ia = Ib Figure 17.12:
> A voltage DV is applied across the ends of a Nichrome heater wire having a cross-sectional area A and length L. The same voltage is applied across the ends of a second Nichrome heater wire having a cross-sectional area A and length 2L. Which wire gets ho
> A high - end gas stove usually has at least one burner rated at 14000 Btu/h. (a) If you place a 0.25-kg aluminum pot containing 2.0 liters of water at 20.°C on this burner, how long will it take to bring the water to a boil, assuming all the heat from th
> Suppose an electrical wire is replaced with one having every linear dimension doubled (i.e., the length and radius have twice their original values). Does the wire now have (a) More resistance, (b) Less resistance, or (c) The same resistance than before?
> All electric devices are required to have identifying plates that specify their electrical characteristics. The plate on a certain steam iron states that the iron carries a current of 6.00 A when connected to a source of 1.20 x 102 V. What is the resista
> In Figure 17.9b does the resistance of the diode (a) Increase or (b) Decrease as the positive voltage DV increases? Figure 17.9:
> Look at the four “circuits” shown in Figure 17.6 and select those that will light the bulb. Figure 17.6:
> Suppose a current-carrying wire has a cross-sectional area that gradually becomes smaller along the wire so that the wire has the shape of a very long, truncated cone. How does the drift speed vary along the wire? (a) It slows down as the cross section b
> The diameter of wire A is greater than the diameter of wire B, but their lengths and resistivities are identical. For a given voltage difference across the ends, what is the relationship between PA and PB, the dissipated power for wires A and B, respecti
> Consider positive and negative charges all moving horizontally with the same speed through the four regions in Figure 17.2. Rank the magnitudes of the currents in these four regions from lowest to highest. (Ia is the current in Figure 17.2a, Ib the curre
> A parallel-plate capacitor is disconnected from a battery, and the plates are pulled a small distance farther apart. Do the following quantities increase, decrease, or stay the same? (a) C (b) Q (c) E between the plates (d) ΔV (e) PEC
> A capacitor is designed so that one plate is large and the other is small. If the plates are connected to a battery, (a) The large plate has a greater charge than the small plate, (b) The large plate has less charge than the small plate, or (c) The plate
> An electron initially at rest accelerates through a potential difference of 1 V, gaining kinetic energy KEe, whereas a proton, also initially at rest, accelerates through a potential difference of -1 V, gaining kinetic energy KEp. Which of the following
> When you jog, most of the food energy you burn above your basal metabolic rate (BMR) ends up as internal energy that would raise your body temperature if it were not eliminated. The evaporation of perspiration is the primary mechanism for eliminating thi
> A spherical balloon contains a positively charged particle at its center. As the balloon is inflated to a larger volume while the charged particle remains at the center, which of the following are true? (a) The electric potential at the surface of the ba
> Consider a collection of charges in a given region and suppose all other charges are distant and have a negligible effect. Further, the electric potential is taken to be zero at infinity. If the electric potential at a given point in the region is zero,
> If a negatively charged particle is placed at point B in Figure 16.3 and given a very small kick to the right, what will its subsequent motion be? Will it (a) Go to the right and not return, (b) Go to the left, (c) Remain at point B, or (d) Oscillate aro
> Figure 16.3 is a graph of an electric potential as a function of position. If a positively charged particle is placed at point A, what will its subsequent motion be? Will it (a) Go to the right, (b) Go to the left, (c) Remain at point A, or (d) Oscillate
> If a negatively charged particle is placed at rest in an electric potential field that increases in the positive x - direction, will the particle (a) Accelerate in the positive x - direction, (b) Accelerate in the negative x - direction, or (c) Remain at
> Consider a parallel-plate capacitor with a dielectric material between the plates. If the temperature of the dielectric increases, does the capacitance (a) Decrease, (b) Increase, or (c) Remain the same?
> A fully charged parallel-plate capacitor remains connected to a battery while a dielectric is slid between the plates. Do the following quantities increase, decrease, or stay the same? (a) C (b) Q (c) E between the plates (d) ΔV (e) PEC
> If an electron is released from rest in a uniform electric field, does the electric potential energy of the charge – field system (a) Increase, (b) Decrease, or (c) Remain the same?
> Find the electric flux through the surface in Figure 15.28. Assume all charges in the shaded area are inside the surface. (a) -(3 C)/є0 (b) (3 C)/є0 (c) 0 (d) -(6 C)/є0 Figure 15.28:
> Suppose the electric field of Quick Quiz 15.7 is tilted 60° away from the positive z - direction. Calculate the magnitude of the flux through the same area. (a) 0 (b) 10.0 N · m2/C (c) 20.0 N · m2/C (d) More information is needed Electric Field in Quick
> A 40.-g block of ice is cooled to -78°C and is then added to 560 g of water in an 80.-g copper calorimeter at a temperature of 25°C. Determine the final temperature of the system consisting of the ice, water, and calorimeter. (If not all the ice melts, d
> Calculate the magnitude of the flux of a constant electric field of 5.00 N/C in the z - direction through a rectangle with area 4.00 m2 in the x y - plane. (a) 0 (b) 10.0 N · m2/C (c) 20.0 N · m2/C (d) More information is needed
> Rank the magnitudes of the electric field at points A, B, and C in Figure 15.15, with the largest magnitude first. (a) A, B, C (b) A, C, B (c) C, A, B (d) The answer can’t be determined by visual inspection. Figure 15.15:
