What happens to the internal energy of water vapor in the air that condensesl( ;du7bmgw pegiy h.rc45 i7*a53mlh on the outside of a cold glass of water? Is work done or heat exchangedhu55bem34ggc.i 7 d*pwm i;7lhy(lra ? Explain.

Use the conservation of energy to explain why the temperature of a gas inb); vz,e: 4. mvkiyuibcreases when it is quickly compressed — say, by pushing down on a cylinder — whereas the temperature decreas,biuvk4.b)v;my e: zi es when the gas expands.

In an isothermal process, 3700;lp9nm vi n 0234w:osggusbw0hi1.w d J of work is done by an ideal gas. Is this enoughdw1 gs blv9;2um.0g4o:w30wn npisi h information to tell how 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 though ni,-jvf0 3,c n*y y6a phxt,u72hrpeeheat flows into or out of it?cex -pua,jh3p*6h n,nf70tey vr2iy, If so, give one or two examples.

Explain why the temperature of a gas increases when it is ap3yrw o. edp.)diabatically compresse3.yp).opdr e wd.

Can mechanical energy ever be transformpqrv1filkut k t;r+ f0q2m.8 j6qh8( ped completely into heat or internal energy? Can the reverse happen? In each caseq; u ffl8t6vr mki.8 +j0hprq2ktq(1p, if your answer is no, explain why not; if yes, give one or two examples.

Can you warm a kitchen in win;-df w) gw/ z5h9lom/ 6r2o4cezslcwmter by leaving the oven door open? Can you cool the kitchen on a hot summer day by leaving the refrigera/c6lz/ dg95hw4oo) swef m;r 2c lz-mwtor door open? Explain.

Would a definition of heat engu-nz,or v(/ni ine efficiency as $e=W/Q_L$ be useful? Explain.

What plays the role of high-temperature a( 0 fo unf9tlr7dy(c,c5sot-fnd low-temperature areas in (a) an internal combustion engin9 o l su fr(n,dycc5o-t(ff70te, and (b) a steam engine?

Which will give the greater improvement in the efficiency of a Carnotjy4s ax( mdl p0u 4u:5zfg9w5j engine, a 10 5fu(u4 s0jjdw z4axlg y5pm:9 $C^{\circ}\,$ increase in the high-temperature reservoir, or a 10 $C^{\circ}\,$ decrease in the low-temperature reservoir? Explain.

The oceans contain a tremendous amount 7vswj 6f/u )qufxq e-j82pi y8of thermal (internal) energy. Why, in general, is it not possible to put this energy to useful wou8) / xw7jeq -fvsqp26iujyf8rk?

A gas is allowed to expand (a) au;,bjh284:b c /*u m 8-ffrq3 xr gwghvhg3itmdiabatically and (b) isothermally. In each process, does the entropy increase, decrease, or stay the samei r8482:qu3v hb/gj f*3b -;u rtfg,xhhw gcmm? Explain.

A gas can expand to twice its origo dit nda:m:g,w+2w2kinal volume either adiabatically or isothermally. Which process would result in a greater change in entropy?g n:k2m ot +iaw2,:dwd Explain.

Give three examples, oz0q(0fjm.x( gdzr(- w2dmsdzk mpe52 ther than those mentioned in this Chapter, of naturally occurring .d (e20x zdr2 zfdqjmz0sgp-( k w5mm(processes in which order goes to disorder. Discuss the observability of the reverse process.

Which do you think has the greater entropy, 1 kg of solid iron or 1 kg of l2 se yg-3*eiqq3 xzi)ziquid ixzq3yzei*e -) gsiq 23ron? Why?

(a) What happens if you remove a3yo+hqevtq, ( a*.qb the lid of a bottle containing chlorine gas? (b) Does the reverse process ever happen? Why or why no*.q (+q,3qveo h tybaat? (c) Can you think of two other examples of irreversibility?

You are asked to test a machine that the inventor calls an “in-room air condijx51dexh ;92v(t caqftioner”: a big box, standing in the middle of the room, with a cable that plugs into a power outlet. When the machine ista ;dh xv51(jex29f qc switched on, you feel a stream of cold air coming out of it. How do you know that this machine cannot cool the room?

Think up several processes e 7zpvg/e3wkq4e2q 9 o(other than those already mentioned) that would obey the first law of thermodynamics, but, if they actually occurred, would violate the s e3po g/7z49k2evwqqeecond law.

Suppose a lot of papxj3qu ii4.af8ers are strewn all over the floor; then you stack them neatly. Does this violate the second law f4i8qj.a ui3xof thermodynamics? Explain.

The first law of thermodynamics is sometimes whimsically stated as, “You;5w5vk 1h0 vneg5*xyox h6zla5iv2 lh can’t get something for nothing,” and the sev*nyx5 o6hv;he g 51iha2w5k0l5 lxvzcond 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 us in wh:zr dwcyij,s89;xs ) h tjj,pls;nd4e.b*m)x ich direction natural processes occur. If a movie were run backward, name some processes that you might see that would tell you that time was “running bajl js:y; t4wx*,pei .d,hcr9)x jmb 8dnsz;s)ckward.”

Living organisms, as they grow, convert ab epwbvq02a+7 3+tm g)3 cpxmm55 qkqrelatively simple food molecules into a complep e0 vxqq5 + 32macb7wq 5ka+pm)3bmgtx structure. Is this a violation of the second law of thermodynamics?

  An ideal gas expands isothermag/wg 3e7 o/bqtlly, performing $ 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 mw9 .kq1l09v/evkx kj yaintained at atmospheric pressure. When 1400 kcal of heat is added to the gas, the vovwl qk k/0xe.9 v91yjklume is observed to increase slowly from $12m^3$ 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 constant yyy2: :4g44 bwp6rlxx;colxanm *er/pressure until its volume is halved, and then it is allowed to expand isothermally bn: gxpybwol4x 4yly;ar/xcm2*r :64eack to its original volume. Draw the process on a PV diagram.

Sketch a PV diagram of the following process: 2.0 L of ,a lw 52q9xujnideal gas at atmospheric pressure are cooled at constant pressure to a volume of 1.0 L, and then expanwux25 ,aq 9ljnded 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 f o0t,e tkjav j*j54 ;s1yow:xinitially at 4.5 atm of (absolute) pressure 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 on a PV diagram, including numbers and labels for ths0w y xo4;tj ov,t:f*5ejkj a1e axes.

  The pressure in an ideal gas is cut in half slowly, while beinx*z cc+80d3 ucps*htyg kept in a container with ctdc+*cux*yp 3h0z8srigid 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 ideal gas is comprest . y((vbc;pntsed adiabatically to half its volume. In doing so, 1850 J of wort. cv(p(tb y;nk 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; sy. *ptz(mgo a constant total 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 originpo .m*g styz;(al value. Calculate
(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 q-6eyd ph+ 2iwideal monatomic gas expand adiabatically, performing 7500 J of work in the process. What is the change in temperature of t -ywh+p2ed6 qihe gas during this expansion?   $ K$

  Consider the following two-step process. Heat is allowed to 4u l.x4p) a27q jcyiawflow out of an ideal gas at constant volume so that its pressure drops from 2.2 atm to 1.4 atm. Then the gas expands at consti4l 2wp.yjxa)q4 ac7uant 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. 151r 4.du 1tt4ign ycm5p–23 shows two possible states of a system containing 1.35 moles ofmugdc4.rtniyt4 1p 15 a monatomic ideal gas.$(P_1\,=\,P_2\,=\,455N/m^2,V_1\,=\,2.00m^3,V_2\,=\,8.00m^3)$
(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 k7 5sux3qgox)v 8f6 v6zvrm(mwork done by the g6)ko7z gmvxu mvf63x s5r( v8qas 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 t-j3imgg7p p4aj84 hgyk.x 3c/qn1p tstate a to state c along the curved path shown in Fip7j nj.mcg3xtgghipa 4 - /tky8413pqg. 15–24, 80 J of heat leaves the system 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 Exampy k azw8pll)k;5+ xu.venbvt ;)5aqv,f*3v ib le 15–8 transform if instead of working 11.0 h she took a noontw abkvv5,bl)3l fat5xn.y; v *)i pvkez qu8;+ime break and ran for 1.0 h?    $ \times10^{ 7}J$

  Calculate the average metabolic rate of a person who sleeps 8.0 h, si0 s7 if-*ouifnts at a desk 8.0 h, engagesf0- o7*fsiui n in light activity 4.0 h, watches television 2.0 h, plays tennis 1.5 h, and runs 0.5 h daily.    $W$

  A person decides to lose jg3gth 5,/tnm weight by sleeping one hour less per day, using the time for, n5t/j3tgg hm light activity. How much weight (or mass) can 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 82;qy*hg kxpvx j(od rd8qciz; u44)4o300 J of heat while performing 3200 J of useful work. What4u k*rozq ocqhvg d jd)3x8p;4i4x(;y is the efficiency of this engine?    %

  A heat engine does 9200 J of work per cycle while absorbing 22.0 kcal of he kv21yy /gara-at from a high-temperature reservoir. What is the efficiency of this eay kag21y-vr/ngine?    %

  What is the maximum efficiency of a heat engine whose operating te o*kl4 9+xcfsfedj 0y;mperatures are 54e+kxs yd 9 lcoj0;ff*80$^{\circ}\,C$ and 380$^{\circ}\,C$?   %

  The exhaust temperature of a h bzmi.8+egc y)nb4 i(meat engine is 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 /,2 pmq qji.vq(1hmwc) 7 :tgfdh3jsd 75% of its maximum theoretical (Carnot) efficiency between3mh gqihtqj ,/jpscf(7)mw2.: d qd1v temperatures 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 environment be hotter than ahz7vn/6ns1qz z z)9x1 y4zcskl5y h:z mbient temperature. Liquid nitrogen (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 a)sk zl6x1nvq5zy nzy:zh17z4/ zs c 9ht room temperature (293 K) to the liquid nitrogen “fuel” (Fig. 15–25)?    %(Round to the nearest integer)

  A Carnot engine performs work at the rate of 440 kW while using 680 kcal of o( dks+2 :qy.c)6unx d9jhsneheat per second. If the temperature of thnsh k dnou96 )2 (s:dqe.xc+jye heat source is 570$^{\circ}\,C$, at what temperature is the waste heat exhausted?    $^{\circ}\,C$

  A Carnot engine’s operating te dipuq99/c31zz7stjmreswvo0 , 3n6emperatures 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 (qyxfugim:2oc l 4k,jtt1,j;of electric power. Estimate the heat discharged per second, assuming i(2:4t mxtlo fyq c1,g,;ujkjthat the plant has an efficiency of 38%.    $MW$

  A heat engine utilizes a heayyd9 9)c m.7o pt4aq5sv m6uiut 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 hecz2 o s2w)fkezrvd jb9:)e/q(at at 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 plabu z1a+lxjp+ )8kv b )v3+(k0 pygtgrmnt, steam engines work in pairs, the output of heat from one being the approximate heat input of the second. The operating tempk g+ 03gpt(1jk)a lyvbz+mv pur8+b)xeratures 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 c6q awe dr1;rew*dk2,woil is -15$^{\circ}\,C$ and the discharge temperature is 30$^{\circ}\,C$. What is the maximum theoretical coefficient of performance?   

  An ideal refrigerator-freezer operates with a zc/pnkd.stbna 627 1a in a 24$^{\circ}\,C$ room. What is the temperature inside the freezer?    $K$

  A restaurant refrigerator hx nas31jli; 5 t14iuvmas a coefficient of performance of 5.0. If the temperature in the kitchen outside the refrigerator is 2nl41miu xj 13;5vit as9$^{\circ}\,C$, what is the lowest temperature that could be obtained inside the refrigerator if it were ideal?    $^{\circ}\,C$

  A heat pump is used to keep a house warm at 2 e780( upz+kmns,g peq2$^{\circ}\,C$. 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 a)zhbx: sph2hdg 6*gtg g 1;/gzt 0$^{\circ}\,C$ 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 has an efficiency of 35%. If it werehwk*l qpqg616c:o-nw 2 eu r(l possible to run it backward as a heat pump, what would b1ql*go6e6:q cr(n -hwku w lp2e its coefficient of performance?   

  What is the change in entrk)*oi: +qj4se9eg7ejge xyy3- e shztp*.l* qopy of 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 heated kyrrx3jp6 /ap; -ok ,l1zaovsj*-e7ifrom 0$^{\circ}\,C$ to 100°C. Estimate the change in entropy of the water.    $J/K$

  What is the change in entrox,c mbes1rh bsf8ty cq(n084 1py of $1\,m^3$ 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 iexcwk*;4i.p2 0wicq knitial 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 enaxpl2d1 xkz 63ergy KE just before striking the ground and coming to rest. What is the total change in entropy of the dz1kp6lxa2 x3rock plus environment as a result of this collision?

  An aluminum rod conducts/(,2. px a 4jfjjiijdkodf 58f $7.50\,cal/s$ 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 30y,dqja::m:uvwl h 91x$^{\circ}\,C$ 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 alu5lkz6 rxxlrcv:n,x 7: 79g tuiminum at 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 working between heat reservoirs at 970 K and 6fnrxdhb9--at )2kq)z 1sf :bf50 K produces 550 J of work per cycle for a heat idhfk:nbf1 -zrf q9 x)a)2s tb-nput 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 probabilities, k)8tbs*mz:ly89wte )nf 4wm ctp/a9g 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 prwqe/v nfi- fa.x 45c1nb.plx4 x+ 3mqjobability: (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 que lwq1jnqcfnie 4pbm5.x/ x4 x.-va f+3ens, and an ace; and (d) any hand having no two equal-value cards. Discuss your ranking in terms of microstates and macrostates.

  Suppose that you repeatedly shake six coins in your handb y;m7ytb5n *moi3:j z and drop them on the floor. Construct a table showing the numbeymo m t73:bb*i;5jzynr of microstates that correspond to each macrostate. What is the probability of obtaining
(a) three heads and three tails,   /64
(b) six heads?   /64

  Solar cells (Fig. 15–26) ca, x -9x5jpwwevo,) p+sjj glh(n produce about 40 W of electricity per square meter of surface area if directly facing the Sun. How large an area is required to supply the needs of j,xpwgs v eh-jj+o9l( w)px, 5a house that requires $22k\,Wh/day$ Would this fit on the roof of an average house? (Assume the Sun shines about $9h/day$)   $m^2$

  Energy may be stored for usecptb lv15ze,2 :c7-cv if5lbo f8 *pfp during peak demand by pumping water to a high reservoir when demand is low and then releasing it to drive turbines when needed. Suppose water is pumped to a lake 135 m above the turbines at ltof 82ceff,pli 5 p1p5v:c-c7vb *bza 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. 15–2mys+9 qh*) hei7). The water depth is 45 m at the damh9e+qmi h)s* y, 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 an eng,r-ib( : zmnpp4c 2aphine that produces 1.50 MW of usabp: z app-hcm4 nr2ib,(le work while taking in 3.00 MW of thermal energy at 425 K, and rejecting 1.50 MW of thermal 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 of mmid-,e pt d86lhjp,+t w7rse;i92j u0.25 and delivers 220 J of work per cycle per cylinder. When the engine fires at 45 cycles per second, 8j9-d6del m ,pr2m ;jutei, ti+7 phws
(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 eg 4-2wz:z ga9a/rpowthe freezer compartment at a tempr4a:wp2eo wzaz g/g-9erature 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 heat engine could be developed that mup:pnq5i 9(uqk46yu i 4tlb cw; ga53lade use of the temperature difference between water at the surface of the ocean and that severau4ic a5q npi34w;ylq(u 6 gp9b: lk5tul hundred 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 4( fsr4jhk0qtao5 tj 0in opposite directions when they collide and are brought tjrtja t4h04 fkqo5s0 (o rest. Estimate the change in entropy of the universe as a result of this collision. Assume $T\,=\,20^{\circ}\,C$    $J/K$

  A 120-g insulated alumiqgv +bu of,4.unum 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 coefficient of perfoy7q(mp8stmr*4bzl23o4p,2 d ak cwiprmance of an ideal heat pump that extracts heat from zm ci4q kb2tp382*r(,dmspa l4 7owyp 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)hs cphd;ak8)3v+ rmaof 4du: car releases 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 a lower .ducg/g5 rl hh-m,*jmoperating 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 in going from state A 86ocl 7 st+s.v xrk/ -:pm3scimpm-pv to state C in Fig. 15–28 for each of the following processes: (a) ADC, (b) ABC, anvcsstkov/+ms p 8-c:76iplr.xmm3 p -d (c) AC directly.

  A 33% efficient power plant puts out 850 MW of electrical poh ; w3u49-n zvc2fchs2z6bminwer. Cooling towers are used to tacsnh63c fwz zuibh;v94 m 22-nke 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 deliversnxo ub d/33 ,ufib.j1qkh 3oc. energy at 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 that the turbine operates as an ideal.cnxofd/q oubij.133u ,h3bk 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% effx:s3337ur lfv)-jdbscbq 7 sc iciency. Assume the engine’s water tesvb73dls cjs-:3x u )r3c 7qbfmperature of 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 cylindrical ja1b 8jo gs he1k3psy19qr 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 of fat results in abo4waxy:-6 (yc zd sda1go b5)j4nyvo0tut $ 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 pu7x:sz 8v bho1+gkkkiz1,o ;inside 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 door.” The hug /o,q e xgw.l:b5-roymid 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 hr .5bol y -,qx:gwg/eoeat 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 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