What happens to the internal energy of water vapor inr:8 atu ltcqg*,mn:i9 the air that condenses on the outside of a cold glass of water? Is work done or heat exchanged? Ex*qrut8mn lt:ic9 ,:gaplain.

Use the conservation of energy to explain why th jbro:.m8syc7 d5d jl1 e1qc5ue temperature of a gas increases when it is quickly compressed — say, by pushing down on a c1 me1 oruyqs58j5 c:.7cjbdldylinder — whereas the temperature decreases when the gas expands.

In an isothermal process, 3700 J of work is5ssej,p,l q8zgqb)5 kf.eb3l done by an ideal gas. Is this enough information to tell hqep jls 3)5belgs,zfb 5 8,.qkow much heat has been added to the system? If so, how much?

Is it possible for the temperature of a system to remain constant even :if*y*7*q1.ymw fr jav yu4mwthough heat flows into or ouyr1q w7 iua f*wy j**.m:m4vfyt of it? If so, give one or two examples.

Explain why the temperature of a gas increases when it is ad zmzg1 hm4ld+c bewz;b+d* 6e1iabatically compress6 b zbmm1g;z+dh *e e4z1lc+wded.

Can mechanical energy ever be transformed completel:vz e ,h m4y2;7sxmdj 7s3gkmdy into heat or internal energy? Can the reverse happen? In each casdy7 7egd m,;mmzhjkvs4:s x3 2e, if your answer is no, explain why not; if yes, give one or two examples.

Can you warm a kitchen in winter by ea 6/mco)j1wq dy :9paleaving the oven door open? Can you cool the kitchen on a hot summer day by leaving the refrigerator door open? Eq)j mc1a/:eo6d y9wpa xplain.

Would a definition of heat engine efficiency ).*hyb q*nrelas $e=W/Q_L$ be useful? Explain.

What plays the role of high-tempfx+m1:iws p 3xerature and low-temperature areas in (a) an internal combustion engine, and (i wp3f+: x1sxmb) a steam engine?

Which will give the greater improvafbvlt6+* 3chm ilnb, tcg .21ement in the efficiency of a Carnot engine, a blm+v tci hl36ft .2g,b*c n1a10 $C^{\circ}\,$ increase in the high-temperature reservoir, or a 10 $C^{\circ}\,$ decrease in the low-temperature reservoir? Explain.

The oceans contain a tremendous amount of thermal (internal)d5 oj)(3hd*oiq6s 9y5 ;wz -pyvdeztg energy. Why, in general, is it not possible 6wd* hdy ;5z-o9z 5vpeot j)ydi3q( gsto put this energy to useful work?

A gas is allowed to expands.i4.ocnun9op:y1as (a) adiabatically and (b) isothermally. In each process, does the entr4nss.1p. oa:c ioun9y opy increase, decrease, or stay the same? Explain.

A gas can expand to twice its original volume either adiabatically or isothkef )oudd6k12b+n0bpermally. Which process would result in a greater change in k60fb1k p2eb+d) noduentropy? Explain.

Give three examples, other than those mentioned in this Chawjk) -0s,wwgs z )pz04ktsu; cpter, of naturally occurring processes in which order goes to disorder. Discuss the obsezp t0sk-s) 4skzc0ww ;gujw ),rvability of the reverse process.

Which do you think has the greater entropy, 1 kg of solid iron or 1 kg of liqu ,s gui-qmb*ch. 6 gjs7sfp4x.id ih cfx-qsg4*is.,b7 sum6jg. pron? Why?

(a) What happens if you refgw* 5sll, nr uzumw0(n; g7-egh-l9dmove the lid of a bottle containing chlorine gas? (b) Does the reverse process ever happen? Why or why not? (c) Can you think of two other examples ow 5;g rls 0, nzud-l-fuem(*nhl 9gwg7f irreversibility?

You are asked to test a machine that the inventor calls an “in-room air concv/o e o-yi9.nditioner”: a big box, standing in the middle of the room, with a cable that plugs into a power outlet. When the machine is switched on, you feel a stream of cold air coming out of it. How do you know thayv9.c /-eino ot this machine cannot cool the room?

Think up several processes (other than those al rbtubfb6)k/ck9:0 cvn xn56 vready mentioned) that would obey the5bb un0cn/xc k6 brf:)v9t6vk first law of thermodynamics, but, if they actually occurred, would violate the second law.

Suppose a lot of papers are strewn all over63uz7 wra)gsllp)) n cc zk; jpe;d*f84smhq, the floor; then you stack them neatly. Does this violate the second law of 3p4)dp,m)8c j;7s hlu nz rc*)fla;qg sezwk6 thermodynamics? Explain.

The first law of thermodynamics is sometimes (ezpn/ 2nxj6;-.hvco ybnhd , 1(fhsmwhimsically stated as, “You can’t get something for notz sb.h/,f(po 2n6 cj(; v- hhemdnnxy1hing,” and the second law as, “You can’t even break even.” Explain how these statements could be equivalent to the formal statements.

Entropy is often called “time’s arrow” because it tells ut0ld xi1+3z5kuum x) ps in which direction natural processes occur. If a movie were run backwa1k5 +z03utpiu) dxlxmrd, name some processes that you might see that would tell you that time was “running backward.”

Living organisms, as they grow, convert r3b 2 fgy-ulz.telatively simple food molecules into a complex structure. Is this a violation of the second.z f-ul2bg 3yt law of thermodynamics?

  An ideal gas expands isothermally, perfor 00dafh.:i d5ilry 9ghming $ 3.40\times10^{ 3}J$ of work in the process. Calculate
(a) the change in internal energy of the gas,
(b) the heat absorbed during this expansion.    $J$

  A gas is enclosed in a cylinder fitted with a light frictionless piston and mainn-nmx ) 4oc7y5fkj*6a me ks9vtained at atmospheric pressure. When 1400 kcal of heat is added to the gas, the volume is observed to increase slowly fek49 -oj7)5mm v*c6fyk annxsrom $12m^3$ to $18.2m^3$ Calculate
(a) the work done by the gas .   $ \times10^{5 }$
(b) the change in internal energy of the gas.    $ \times10^{ 6}$

One liter of air is cooled at ct 42p98bogb o-0 )j6adrrkxxqonstant pressure until its volume is halved, and then it is allowed to expand isothermally back to itsoj6gqpkt - o8xb a)b409r2drx original volume. Draw the process on a PV diagram.

Sketch a PV diagram of the following process: 2.0 L of ideal gas at atmosphericp(/wy)rtc4m +p 5. 4 hmhyhftl0l0nce pressure are cooled at constant pressure to a volumel 5)cfhy40 tp0ymw( h.+empt4hl /nrc of 1.0 L, and then expanded isothermally back to 2.0 L, whereupon the pressure is increased at constant volume until the original pressure is reached.

A 1.0-L volume of air initially at 4.5 atm of (absolute) pressurefq 7jno7i ;j; x8:bvwo is allowed to expand isothermally until the pressure is 1.0 atm. It is then compressed at constant pressure to its initial volume, and lastly is brought back to its original pressure by heating at constant volume. Draw the process o:ni fo; ;b87 oxj7wvqjn a PV diagram, including numbers and labels for the axes.

  The pressure in an ideal gas is cut in half slowly, while bein9ibpj,xkit 0 4w.n 6fbg kept in a container xbtj9wk i4p0nb ., if6with rigid walls. In the process, 265 kJ of heat left the gas.
(a) How much work was done during this process?    $J$
(b) What was the change in internal energy of the gas during this process?    $kJ$

  In an engine, an almost idzmca 5u r)dq67eal gas is compressed adiabatically to half its volume. In doing so, 18d u rc)7z6m5qa50 J of work is done on the gas.
(a) How much heat flows into or out of the gas?    $J$
(b) What is the change in internal energy of the gas?    $J$
(c) Does its temperature rise or fall? ----待选择----fallrise 

  An ideal gas expands at a constant t) a1nog/zxjixc ,4os0 otal pressure of 3.0 atm from 400 mL to 660 mL. Heat then flows out of the gas at constant volume, and the pressure and temperature are allowed to drop until the temperature reaches its original value. xoni1jc)z/sox0 ga,4Calculate
(a) the total work done by the gas in the process,   $J$
(b) the total heat flow into the gas.    $J$

  One and one-half moles of an ideal monatomic gas expand adiabatically, perr)r:msp-o-f j forming 7500 J of work in the process. Whrfpmo jr-):- sat is the change in temperature of the gas during this expansion?   $ K$

  Consider the following two-step process. Heat is allowed to flow out of d44xxgfp v pi 2h kbu49f9:xb9an ideal gas at conf4ux b9b 49ifdvpgxxhp92 4k:stant volume so that its pressure drops from 2.2 atm to 1.4 atm. Then the gas expands at constant pressure, from a volume of 6.8 L to 9.3 L, where the temperature reaches its original value. See Fig. 15–22. Calculate
(a) the total work done by the gas in the process,    $J$
(b) the change in internal energy of the gas in the process,    $J$
(c) the total heat flow into or out of the gas.    $J$  ----待选择----intoout  the gas

  The PV diagram in Fig. 15–23 shows two possible states of a syste ng-f7h kbz9(zdz;ayaadw*d.2.g v d2-j0tq rm containing 1.35 moles of a monatomic ideal ga.-da .dhrazftj*gyz bavz qnw- d02;kd7g92 (s.$(P_1\,=\,P_2\,=\,455N/m^2,V_1\,=\,2.00m^3,V_2\,=\,8.00m^3)$
(a) Draw the process which depicts an isobaric expansion from state 1 to state 2, and label this process A.
(b) Find the work done by the gas and the change in internal energy of the gas in process A. W =    $J$ $\Delta\,U$ =    $J$
(c) Draw the two-step process which depicts an isothermal expansion from state 1 to the volume $V_2$ followed by an isovolumetric increase in temperature to state 2, and label this process B.
(d) Find the change in internal energy of the gas for the two-step process B.    $J$

  When a gas is taken from a to c along the curved path in Fig. 15–24, the w1/zu qx fx:d8n z +k(iq.o5xxtork done by the gas . oizxu : qq(tnk1dzx+/x5x8f is $W\,=\,-35\,J$ and the heat added to the gas is $Q\,=\,-63\,J$ Along path abc, the work done is $W\,=\,-48\,J$
(a) What is Q for path abc?    $J$
(b) If $P_c\,=\,\frac{1}{2}P_b$ what is W for path cda?    $J$
(c) What is Q for path cda?    $J$
(d) What is $U_a-U_c$?    $J$
(e) If $U_d-U_c\,=\,5J$ what is Q for path da?    $J$

  In the process of taking a gas from state a to state c along the curved pathp(pf d.)d*hvp shown in Fig. 15–24, 80 J of heat leaves the systh(dp fp)pv.d* em and 55 J of work is done on the system.
(a) Determine the change in internal energy, $U_a-U_c$.    $J$
(b) When the gas is taken along the path cda, the work done by the gas is How much heat Q is added to the gas in the process cda?    $J$
(c) If $ P_a\,=\,2.5P_d$ how much work is done by the gas in the process abc?    $J$
(d) What is Q for path abc?    $J$
(e) If $U_a-U_b\,=\,10\,J$ what is Q for the process bc?    $J$
Here is a summary of what is given:
$\begin{aligned}
Q_{\mathrm{a} \rightarrow \mathrm{c}} & =-80 \mathrm{~J} \\
W_{\mathrm{a} \rightarrow \mathrm{c}} & =-55 \mathrm{~J} \\
W_{\mathrm{cda}} & =38 \mathrm{~J} \\
U_{\mathrm{a}}-U_{\mathrm{b}} & =10 \mathrm{~J} \\
P_{\mathrm{d}} & =2.5 P_{\mathrm{d}} .
\end{aligned}$

  How much energy would the person of Example 1 t vg6 jkh2ssy4js56/h5–8 transform if instead of working 11.056gy j42hs6 stkvj/s h h she took a noontime break and ran for 1.0 h?    $ \times10^{ 7}J$

  Calculate the average metabolic rate of a person who slee912njl6gi/vefpdwq (rm2;f me3v m:tps 8.0 h, sits at a desk 8.0 h, engages in light activity 4.0 h, watches television 2.0 h, plays tennis 1.5 h, and runs 0.5 h dailmm2mwrjevfg;6t/ q elniv ( 9:d 21p3fy.    $W$

  A person decides to l.sq fndf, 1w/1 vc+wfq*/ :tvbp/umq tose weight by sleeping one hour less per day, using the time for light activity. How much weight (or mass) c:w*.q +/nd/qfs wtpf 1 vbv,qm1/f utcan this person expect to lose in 1 year, assuming no change in food intake? Assume that 1 kg of fat stores about 40,000 kJ of energy.   kg(retain one decimal places)    $lbs$

  A heat engine exhausts 8200 J of4o)uat7uuik /mvk)6om 2ei2p o /d km3 heat while performing 3200 J of useful work. What is t32oomut/k /k)pm odav76iu2mu eik) 4he efficiency of this engine?    %

  A heat engine does 9200 J of work pkw of:,5y joc6er cycle while absorbing 22.0 kcal of heat from a high-temperature reservoir. What is the efficiency of th, o65 ock:jfwyis engine?    %

  What is the maximum efficiency of a heat engine whose o/yi 71sf -uq*v tswo ne/wl:5operating temperatures arewqie7 t*l-/wvsosy5 n1o/uf: 580$^{\circ}\,C$ and 380$^{\circ}\,C$?   %

  The exhaust temperature of a heat engine psus+l 5wl(fmx29kfh p hp/ 42is 230$^{\circ}\,C$. What must be the high temperature if the Carnot efficiency is to be 28%?    $^{\circ}\,C$

  A nuclear power plant operates at 75% of itjnx +itx 933 wkten*4hs maximum theoretical (Carnot) efficiency between temperatures netxi4+*k3jt xwnh 93 of 625$^{\circ}\,C$ and 350$^{\circ}\,C$. If the plant produces electric energy at the rate of 1.3 GW, how much exhaust heat is discharged per hour?    $ \times10^{13 }J/h$

  It is not necessary that a heat engine’s hot e-8j clayfnhz)tq8w: q1g v93lnvironment be hotter than ambient temperature. Liquid ny1hll3wqq8ng:vazt)-9f 8 jcitrogen (77 K) is about as cheap as bottled water. What would be the efficiency of an engine that made use of heat transferred from air at room temperature (293 K) to the liquid nitrogen “fuel” (Fig. 15–25)?    %(Round to the nearest integer)

  A Carnot engine performs pzqp 1*ubg,9gwork at the rate of 440 kW while using 680 kcal of heat per second. If the temperature of the heag,uqb* pp z1g9t source is 570$^{\circ}\,C$, at what temperature is the waste heat exhausted?    $^{\circ}\,C$

  A Carnot engine’s operating te w h vt78:xggu(i3d wm2,l6fp;zpw:qvmperatures are 210$^{\circ}\,C$ and 45$^{\circ}\,C$. The engine’s power output is 950 W. Calculate the rate of heat output.    $W$

  A certain power plant puts out 550 MW of electric power. Estimn v( l*wwc64mkwb tiv68 qux73ate the heat discharged per second, assuming that the plant has an evk4t ivbx(lw6n7*38 mqcwu w 6fficiency of 38%.    $MW$

  A heat engine utilizes a hel ejk(lo1yfb b* +5mt7at source at 550$^{\circ}\,C$ and has an ideal (Carnot) efficiency of 28%. To increase the ideal efficiency to 35%, what must be the temperature of the heat source?    $^{\circ}\,C$

  A heat engine exhausts its heat at9a;-ha0 qjo,+amapmx 350$^{\circ}\,C$ and has a Carnot efficiency of 39%. What exhaust temperature would enable it to achieve a Carnot efficiency of 49%?    $^{\circ}\,C$

  At a steam power plant26; kjlo 6wl9vu6m unf, steam engines work in pairs, the output of heat from one being the approximatulvu6jlk9wmf26 o; n6e heat input of the second. The operating temperatures of the first are 670$^{\circ}\,C$ and 440$^{\circ}\,C$, and of the second 430$^{\circ}\,C$ and 290$^{\circ}\,C$. If the heat of combustion of coal is $ 2.8\times10^{7 }\,J/kg$ at what rate must coal be burned if the plant is to put out 1100 MW of power? Assume the efficiency of the engines is 60% of the ideal (Carnot) efficiency.    $kg/s$

  The low temperature of a freezer cooling coil is -15 m6-2 :fmbjnkhjh q4o ;tvpb0x-s*n-y$^{\circ}\,C$ and the discharge temperature is 30$^{\circ}\,C$. What is the maximum theoretical coefficient of performance?   

  An ideal refrigeratom5o(yv; g v5,deebx/jr-freezer operates with a in a 24$^{\circ}\,C$ room. What is the temperature inside the freezer?    $K$

  A restaurant refrigerator has a coef42if3 s1v bzefficient of performance of 5.0. If the temperature in the kitchen outside the refrigerator is 2vzif34b 1fe s29$^{\circ}\,C$, what is the lowest temperature that could be obtained inside the refrigerator if it were ideal?    $^{\circ}\,C$

  A heat pump is used tcj7j ilhc0 ;6kpvag 40ce9u 3bo keep a house warm at 22$^{\circ}\,C$. How much work is required of the pump to deliver 2800 J of heat into the house if the outdoor temperature is
(a) 0$^{\circ}\,C$,    $J$
(b) -15$^{\circ}\,C$ Assume ideal (Carnot) behavior.    $J$

  What volume of water at f):t:ml6q vw qnls)h60$^{\circ}\,C$ can a freezer make into ice cubes in 1.0 hour, if the coefficient of performance of the cooling unit is 7.0 and the power input is 1.0 kilowatt?    $L$

  An ideal (Carnot) engine hagd6/l z3vwfhv35st 4 ta.e*nj2zxjr8s an efficiency of 35%. If it were possible to run it backward as a heat pump, whht 3vzs. av zwd/f8jen6*5gx42r3 l jtat would be its coefficient of performance?   

  What is the change in entropy dcxglqtbxpnc 20h7,ia ) o5 04of 250 g of steam at 100$^{\circ}\,C$ when it is condensed to water at 100$^{\circ}\,C$?    $J/K$

  One kilogram of water is heatedwjwm8 ,yx f p2:9bvt3t from 0$^{\circ}\,C$ to 100°C. Estimate the change in entropy of the water.    $J/K$

  What is the change in entropy of efgduwumw8) 4 .i-/mm$1\,m^3$ of water at 0$^{\circ}\,C$ when it is frozen to ice at 0$^{\circ}\,C$?   $ \times10^{6 }\, J/K $

  If $1.00\,m^3$ of water at 0$^{\circ}\,C$ is frozen and cooled to -10$^{\circ}\,C$ by being in contact with a great deal of ice at -10$^{\circ}\,C$ what would be the total change in entropy of the process?   $J/K$

  A 10.0-kg box having an initian u thynptk(2v0yzrf19/d b6(l speed of $3.0m/s$ slides along a rough table and comes to rest. Estimate the total change in entropy of the universe. Assume all objects are at room temperature (293 K).   $J/K$

A falling rock has kinetic energy KE just u-x- ts3n nc/+rc8ptr before striking the ground and coming to rest. What is the total change in entropy of the rock plus environment as a resultpt cc r-r-3n8s+/untx of this collision?

  An aluminum rod conducx qdxfa8a 2/0y*(dg;x* yhg zzts $7.50\,cal/s$ from a heat source maintained at 240$^{\circ}\,C$ to a large body of water at 27$^{\circ}\,C$. Calculate the rate entropy increases per unit time in this process.   $\frac{J/K}{s}$

  1.0 kg of water at 30on/qq4 bs:us* $^{\circ}\,C$ is mixed with 1.0 kg of water at 60$^{\circ}\,C$ in a well-insulated container. Estimate the net change in entropy of the system.    $J/K$

  A 3.8-kg piece of aluminum ata2 ecd( 9, yqt87tdtu4lvnu5e 30$^{\circ}\,C$ is placed in 1.0 kg of water in a Styrofoam container at room temperature (20$^{\circ}\,C$). Calculate the approximate net change in entropy of the system.    $J/K$

  A real heat engine workioap d;2:b u+exng between heat reservoirs at 970 K and 650 K produces 550 J of work per cycle for 2:eb;up+xado a heat input of 2200 J.
(a) Compare the efficiency of this real engine to that of an ideal (Carnot) engine.    % of ideal(Round to the nearest integer)
(b) Calculate the total entropy change of the universe per cycle of the real engine.    $J/K$
(c) Calculate the total entropy change of the universe per cycle of a Carnot engine operating between the same two temperatures.   

  Calculate the probabili x0 9d.npz2choties, when you throw two dice, of obtaining
(a) two numbers totaling 5. The probability is 1/  
(b) two numbers totaling 11. The probability is 1/  

Rank the following five-card hands in order of increasing probabn6ejyls ut9 o-- h87tqility: (a) four aces and a king; (b) six of hearts, eight of diamonds, queen of clubs, three of hearts, jack of spades; (c) two jacks, two queens, and an ace; and (d) any hand having no two equal-value6 ny qt8 -os-9ulhjt7e cards. Discuss your ranking in terms of microstates and macrostates.

  Suppose that you repeatedly shake six coins in your hand and drop them on the d4wp:hpvb.v w jqc)5p nup9n5d1 b.w7floor. Construct a table showing the number of microstates that correspond to each macrostate. What is the probability odb p5 517un )q9npp:bvvdc wh 4w.jw.pf obtaining
(a) three heads and three tails,   /64
(b) six heads?   /64

  Solar cells (Fig. 15–26) can produce about 40 W of electric+nq iea8o b3w3ity per square meter of surface area if directly facing the Sun. How large an area is required to supply the needs of a house that req beowiaq338+nuires $22k\,Wh/day$ Would this fit on the roof of an average house? (Assume the Sun shines about $9h/day$)   $m^2$

  Energy may be stored for use during peak demand by pumping water to a cse h*ue/jp/) high reservoir when demand is low and then releasing it to drive turbines when needed. Suppose water is pumped to a lake 135 meushj/ /)cp*e above the turbines at a rate of $ 1.00\times10^{ 5}kg/s$ for 10.0 h at night.
(a) How much energy (kWh) is needed to do this each night?    $\times10^{9 }W\cdot\,h$
(b) If all this energy is released during a 14-h day, at 75% efficiency, what is the average power output?    kW

  Water is stored in an artificial lake created by a dam (Fig. 15–27). The wad:je + a+cn/9 wzps6mnter depth is 45 m at tns +: 6d/z meajp+cnw9he dam, and a steady flow rate of $35m^3/s$ is maintained through hydroelectric turbines installed near the base of the dam. How much electrical power can be produced?    $ \times10^{7 }W$

  An inventor claims to have designed and built ,:ftz/cnl 9. gohg9m uan engine that produces 1.50 MW of usable work while taking in 3.00 MW of thermal energy at 425 K, and rejecting 1.50 MW of thermal hgo9cl:gun 9zmt /.,f energy at 215 K. Is there anything fishy about his claim? Explain.  ----待选择----yesno 

  When $ 5.30\times10^{ 4}J$ of heat is added to a gas enclosed in a cylinder fitted with a light frictionless piston maintained at atmospheric pressure, the volume is observed to increase from $1.9m^3$ to $4.1m^3$ Calculate
(a) the work done by the gas,    $ \times10^{5 }J$
(b) the change in internal energy of the gas.    $ \times10^{5 }J$
(c) Graph this process on a PV diagram.

  A 4-cylinder gasoline engine has an efficiency o(9..bum-g+ ikbpwrhm : 2jtglf 0.25 and delivers 220 J of work per cycle per cpg gl-b.. 9r2 uj:+( khmibtmwylinder. When the engine fires at 45 cycles per second,
(a) what is the work done per second?    $ \times10^{4 }J/s$
(b) What is the total heat input per second from the fuel?    $ \times10^{5 }J/s$
(c) If the energy content of gasoline is 35 MJ per liter, how long does one liter last?    s

  A “Carnot” refrigerator (the reverse of a Carnot engine) absorbs heat from sds4sqoz 0f 42the freezer compar s z40fsdo4sq2tment at a temperature of -17$^{\circ}\,C$ and exhausts it into the room at 25$^{\circ}\,C$.
(a) How much work must be done by the refrigerator to change 0.50 kg of water at 25$^{\circ}\,C$ into ice at -17$^{\circ}\,C$    $ \times10^{4 }J$
(b) If the compressor output is 210 W, what minimum time is needed to accomplish this?    s

  It has been suggested that a hetv 8vzmw8)exfcr 76,: bxf w7eat engine could be developed that made use of the temperature difference between water at the surface of the ocean and that several huw 7zmfetxcfv we67,) xr:8bv8ndred meters deep. In the tropics, the temperatures may be 27$^{\circ}\,C$ and 4$^{\circ}\,C$, respectively.
(a) What is the maximum efficiency such an engine could have?    %
(b) Why might such an engine be feasible in spite of the low efficiency?
(c) Can you imagine any adverse environmental effects that might occur?

  Two 1100-kg cars are traveling in opposite dip.h:ppug t5x3 rections when they collide and are brought to rest. Estimate the change in entropy g upp. x3t:5phof the universe as a result of this collision. Assume $T\,=\,20^{\circ}\,C$    $J/K$

  A 120-g insulated alumin0bl2dbu -ss)q gvu v14um cup at 15$^{\circ}\,C$ is filled with 140 g of water at 50$^{\circ}\,C$. After a few minutes, equilibrium is reached.
(a) Determine the final temperature,    $^{\circ}\,C$
(b) estimate the total change in entropy.    $J/K$

  (a) What is the coefw*3cbh18qj. b 1akzynficient of performance of an ideal heat pump that extracts heat fromcn zhqabk*18jby 13w. 6$^{\circ}\,C$ air outside and deposits heat inside your house at 24$^{\circ}\,C$?   
(b) If this heat pump operates on 1200 W of electrical power, what is the maximum heat it can deliver into your house each hour?    $ \times10^{ 7}J$

  The burning of gasoline in a car releas f;i: )xs4e i,jvvbnkvx/ ;)qles about $ 3.0\times10^{ 4}kcal/gal$ If a car averages $41km/gal$ when driving $90km/h$ which requires 25 hp, what is the efficiency of the engine under those conditions?    %

  A Carnot engine has ue.wfw3w/tb2bpwm4w-s j* lf7/u; dq a lower operating temperature $T_L\,=\,20^{\circ}\,C$ and an efficiency of 30%. By how many kelvins should the high operating temperature $T_H$ be increased to achieve an efficiency of 40%?    $K$

Calculate the work done by an ideal gas i;o17iolc kxmgxc5 (43wa y1x2k in8kn n going from state A to state C in Fig. 15–28 for each of the following processes: (a) ADC, (b) ABC, a k5x4nm nxk l18wi3(io2xckc1 ;yag 7ond (c) AC directly.

  A 33% efficient power plant puts out 850 MW5up;fs ts/k8 1ki(o py of electrical power. Cooling towers are u1sy8/pk ufpoi ts(k;5 sed to take away the exhaust heat.
(a) If the air temperature is allowed to rise 7.0 $C^{\circ}\,$, estimate what volume of air $(LM^3)$ is heated per day. Will the local climate be heated significantly? $\approx$   $km^3/day$(Round to the nearest integer)
(b) If the heated air were to form a layer 200 m thick, estimate how large an area it would cover for 24 h of operation. Assume the air has density $1.2kg/m^3$ and that its specific heat is about $1.0KJ/kg\cdot\,C$ at constant pressure.    $km^2$

  Suppose a power plant delivers energy at0w 7gd3i j8ses 980 MW using steam turbines. The steam goes into the turbines superheated at 625 K and deposits its unused heat in river water at 285 K. Assume tha s3s0egw i8dj7t the turbine operates as an ideal Carnot engine.
(a) If the river flow rate is $37m^3/s$ estimate the average temperature increase of the river water immediately downstream from the power plant.    $C^{\circ} $
(b) What is the entropy increase per kilogram of the downstream river water in $J/kg \cdot\,K?$    $J/kg\cdot\,K$

  A 100-hp car engine operates at about 15% efficiency. Assume the engini:sd wn u8c+oo:bb 7:te’s water temperature o ni:bdcub7: oo8 :tsw+f 85$^{\circ}\,C$ is its cold-temperature (exhaust) reservoir and 495$^{\circ}\,C$ is its thermal “intake” temperature (the temperature of the exploding gas–air mixture).
(a) What is the ratio of its efficiency relative to its maximum possible (Carnot) efficiency?    %
(b) Estimate how much power (in watts) goes into moving the car, and how much heat, in joules and in kcal, is exhausted to the air in 1.0 h.P =    W $Q_L$ =    $ \times10^{ 9}J$ $Q_L$ =    $ \times10^{5 }kcal$

  An ideal gas is placed in a tall cylins.6wzr1 gos 6 qohv(/ wez5xf5drical jar of cross-sectional area $0.800m^2$ A frictionless 0.10-kg movable piston is placed vertically into the jar such that the piston’s weight is supported by the gas pressure in the jar. When the gas is heated (at constant pressure) from 25$^{\circ}\,C$ to 55$^{\circ}\,C$, the piston rises 1.0 cm. How much heat was required for this process? Assume atmospheric pressure outside.    $J$

  Metabolizing 1.0 kg o8-t1ahn b ;lqsk1:zm yf fat results in about $ 3.7\times10^{7 }J$ of internal energy in the body.
(a) In one day, how much fat does the body burn to maintain the body temperature of a person staying in bed and metabolizing at an average rate of 95 W? $\approx$ =    $kg/d$(retain two decimal places)
(b) How long would it take to burn 1.0-kg of fat this way assuming there is no food intake?    d

  An ideal air conditioner keeps the temperature i ygse+fp 5u jox31 uih5zzpbh2f.123knside a room at 21$^{\circ}\,C$ when the outside temperature is 32$^{\circ}\,C$. If 5.3 kW of power enters a room through the windows in the form of direct radiation from the Sun, how much electrical power would be saved if the windows were shaded so that the amount of radiation were reduced to 500 W?    W

  A dehumidifier is essentially a “refrigerator with an open do s88ypm; vxb8k k(,cayor.” The humid air is pulled in by a fan and guided to a cold coil, where the temperature is less than the dew point, and some of the air’s water condenses. After this water is extracted, the air is warmed back to its original temperature and sent into the room. In a well-designed dehumidifier, the heat is exchanged between the incoming and outgoing air. This way the heat that is removed by the refrigerator coil mostly comes from the condensation of water vapor to liquid. Estimate how much water is removed in 1.0 h by an ideal dehumidifier, if the temperature s ap88; kyyx(8cmkvb, of the room is 25$^{\circ}\,C$, the water condenses at 8$^{\circ}\,C$, and the dehumidifier does work at the rate of 600 W of electrical power.    kg