What happens to the internal energy of *b,l 89jng hizwater vapor in the air that condenses on the outside of a cold glass of water? Is work donji gn,8*9bhlze or heat exchanged? Explain.

Use the conservation of energy to explain why the temperature ofq/d(gk7vkd 7hf 8p* miciu 87d a gas increases when it is quickly compressed — say, by pushing down on a cylinder — whereas the temperature decreases when the gas /8du d*8 dpqmvif(k i7cgk h77expands.

In an isothermal process, 3700 J of work is done0s dozcm0m 4thn; 5e3qw0 almr4i nv59 by an ideal gas. Is this enough information to tell how much zev d54w3tco;4m9ra0inl 0sqhn mm05 heat has been added to the system? If so, how much?

Is it possible for the temperature of a system to remain constan ,pzs*8cl d0;uhn ii8gt even though heat flows into or lhsi c,88pgin* d ;0uzout of it? If so, give one or two examples.

Explain why the temperature of a gas increases when it is adiabatically compresfhnec0:w zm: 2se f:2mw:0zehcn d.

Can mechanical energy ever be transformed completely into heat or intol86svan/u l/ xfm9w; ernal energy? Can the reverse happen? In each case, if your answer is no, explain why not; if yes, give one or two examples6 ;fou/v ml/xlnwsa89.

Can you warm a kitchen in winter by leaving the oven door open? Cahd cdyn(( -grze31y4rn you cool the kitchen on a hot summer day by lezn(gy rr(ey1d3 hd 4-caving the refrigerator door open? Explain.

Would a definition of heau/y//y 3z9+c1o drztgys +trqt engine efficiency as $e=W/Q_L$ be useful? Explain.

What plays the role of high-temperature m:d wqg68g/zvand low-temperature areas in (a) an internal combustion engine, and (b) a steam enginem/8wvzggq 6:d?

Which will give the greater improvement in the efficiency of a Carnot el s1-e8mc ddd/ngine, a 10 c de8 -sddm/1l$C^{\circ}\,$ 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) zms*3qa-5 8oqkw6brg energy. Why, in general, is it not possible to put this energy 3mzqg w8*5k o-ra6bq sto useful work?

A gas is allowed to expand (a) adiabaticallywta2 +9nti z :fl/-jjn and (b) isothermally. In each process, does the entropy increase, decrease, or stay the-/ i+t9wtz af2njjln : same? Explain.

A gas can expand to twice its original volume either a,sbmq14al8 avdiabatically or isothermally,b mvs4a1a8lq . Which process would result in a greater change in entropy? Explain.

Give three examples, other than those mentioned j4 x3vwg;xjo)zksqeu+. (l/g1 tgwz4 in this Chapter, of naturally occurring processes in which order goes to disorder. Discuss the observability of the revw1wgs)vxguz43e tloqj.4 k xg+ (/z j;erse process.

Which do you think has the greater entropy, 1 kg of solid iron or 1 kg of liquidvmz l3fny)a3gu; ft2 1m9u vu* iro3nug9f uv1* avm;ty) 2zu3mfln? Why?

(a) What happens if you remove the lid of a bottle containing cb sfm7a1nbj-;hlorine gas? (b) Does the reverse process ever happen? Why or why not? (c) Can you think of two oth1-bsamfbn 7;jer examples of irreversibility?

You are asked to test/+h :ph7xc ovf a machine that the inventor calls an “in-room air conditioner”: a big box, standing in the middle of the room, with a cable that plugs intp /hcfxh:+7voo a power outlet. When the machine is 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 (other tdyzadt x7a)j.q 2n4 6nhan those already mentioned) that would obey the first law of thermodynamics, but, if they actually occurred,z47)njt6.nd qa 2dxay would violate the second law.

Suppose a lot of papers;wves .k +)ncj are strewn all over the floor; then you stack them neatly. Does this violate the secojv.sen )+c w;knd law of thermodynamics? Explain.

The first law of thermodynamics is sometimes whimsically stated as,v .j(+2)zcgnpawy. p s “You can’t get something for nothing,” and the second law as, “You can’t even break even.” Explain hogw+)2yca(njp v. ps z.w these statements could be equivalent to the formal statements.

Entropy is often called “;p0i+vzkto -rtime’s arrow” because it tells us in which direction natural processes occur. If a movie were run backward, name some processes that you might see that would tell you that time was “t0-i kzo;rv+prunning backward.”

Living organisms, as they grow, convert relatively simple food molecules i)* v6cp5seon 08hqmsknto a complex structure. Is this a violation of the second law s0p5h)nq* k c86msoev of thermodynamics?

  An ideal gas expands isothermally, performing o,ukfhlzs ;9) $ 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 cylinde,4ja.*ir1nw al .n mder fitted with a light frictionless piston and maintained at atmospheric pressure. When 1400 kcal of heat is added to the gas, the volume is observed to inj1i,. an*.e nwl m4radcrease 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 pres m;xc),u3fwj5hv*l ,9bvf kx.skuq2psure until its volume is halved, and then it w,fmu*ub xvf 3 vxsjqk) pc9;.lh2,k5is allowed to expand isothermally back to its original volume. Draw the process on a PV diagram.

Sketch a PV diagram of the following process: 2.0 L of ideal m 16fwg cs;l9e;bhfm n(ofb36 oj0)lrgas at atmospheric pressure are cooled at constant pressure to a volume of 1.0 L, and then expanded isothermally back to 2.0 L, whereupon t6hll r;0 egb( ocffnf 6);j3bs1mw9om he pressure is increased at constant volume until the original pressure is reached.

A 1.0-L volume of air inz 5cs47 5 ormv (xkuc 8r4;s.clvkzh;zitially 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 constankv mc7c;;r v rko5 4.lu 58ss(hczzx4zt volume. Draw the process on a PV diagram, including numbers and labels for the axes.

  The pressure in an ideal gas is cut in half slowly, while being 4+): bx3fnipmuz7)u ; , yh6qojtjbddkept in a container with rigid walls. In4yjbb6 pd fdjh):t ), 7z;ux3o+qiunm 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 compressed adiabatically to half itm axy4cj r*g;(d8nj2j t8qhyxt kfze2 36(1scs volume. In doing so, 1850 J of work is done on t2cj3t8 48n(d6sx tm 1he jc (ja2qkyy;*gzxrfhe 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 total pressure of 3.0 atm from 400 mLqce 9. buyp;6z b9aj+n 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 reachbn6 p uj.zc +a9by;eq9es its original 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 ideal monatomic gas expa (mo8+y+dvl,zya okf 9nd adiabatically, performing 7500 J of work in the process. What is the change in temperature of the ga 8o+9zodvaf m,y(kl y+s during this expansion?   $ K$

  Consider the following two-shv+r :6lkedxer7-n 8 jtep process. Heat is allowed to flow 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 constant pressure, fd:jev 7+x kl-8reh r6nrom 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 td8qo2xza;t n0k;z* fr wo possible states of a system containing 1.35 moles of a monatomic idxdta0qzon z*kr2 f ;8;eal 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, thmsa7rx:: qr 3ke work done byxa :sr:3qm 7rk the gas 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 aldds1o3s rglgi5 : y6zso,b4r3ong the curved path shown in Fig. 15–24, 80 J of heat leaves the system and 55 J of work is don6,4orory3sib g3 1 s s:5ddlgze 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 persye inu4 7/s u ;6jtn;dgdq1x8mon of Example 15–8 transform if instead of working 11.0 h she took a noontime break and dusiqg6y1j48;xennt m/ ; ud7 ran for 1.0 h?    $ \times10^{ 7}J$

  Calculate the average metabolic rate of a mw; gq71qlgv5o85lj8a 5mrdjperson who sleeps 8.0 h, sits at a desk 8.0 h, engages in light activity 4.0 h, watches television 2.0 h, plays t8 wl g55jaqv;gr51qm oj md7l8ennis 1.5 h, and runs 0.5 h daily.    $W$

  A person decides to lose weight by dx2bavoe 9ae bd 7g3l(. .eit)sleeping one hour less per day, using the time for light activity. How much weight (or mass) can this person expect to lose in 1 year, assuming no change ini b9oede 7.va. be(d axg3t)2l 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 of heat while performing 32jg8 3) ,g cnaof5qh6ne00 J of useful work. What is the effici6j h5f negqg3)ca,no 8ency of this engine?    %

  A heat engine does 9200 J of ouh f ix q)k k/)jk4s-eu4rl6/work per cycle while absorbing 22.0 kcal of heat from a high-temperature reservoir.i)k/koek )srx4uq64u-j l/f h What is the efficiency of this engine?    %

  What is the maximum efficiency of gfqvgww z ef/bjt9+b /a513 x2a heat engine whose operating temperatures are 5 +ge5 jwqg/f atv/zx wbb29f3180$^{\circ}\,C$ and 380$^{\circ}\,C$?   %

  The exhaust temperature of a heat engi.yr dwik+t+ d2sujc0- ne 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 75% of its maximum theoret kh9kcv9 vr,0wj. amyb+ 1ny9bical (Carnot) efficienmk jh.+b9akr w0v1,9 y9b ycvncy between 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 ambz iwcmd43:otge,8 e,za5c ; liient temperature. Liquid nitrogen (77 K) is about as cheap as bottled water. What would be the efficiency of a4wicdl ,o izz5eet3g :ma ,;8cn 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 work at the rate of 440 kW whvv uxr-8l90 fnhf t( e l*t;j7sqnr(u(ile using 680 kcal of heat per second. If the temperature of the hejhn8ne(* 7f q(0vurt -txul9 (fl;rsvat source is 570$^{\circ}\,C$, at what temperature is the waste heat exhausted?    $^{\circ}\,C$

  A Carnot engine’s operating temperature 4bkurf*g7k4 h3 g/ctzb7 ciy1s 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 zd+e*wyi3 6mf out 550 MW of electric power. Estimate the heat discharged per second, assuming that the plant 63eywdi fzm+*has an efficiency of 38%.    $MW$

  A heat engine utilizes a heat source aoun7c niutgtv 9g8s.t fz:9 :8t 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 mq so,yyi) 6/uat 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 plant, steam engines work in pairs, the output o w j cy*,at5.pg0hdk9lf heat from one being the approximate heat input of the second. The operating temperatur5a.,pl khtc wg9d0 jy*es 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 coixbcwhah 6cr:q/cd.5 6l 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 inq (0zi/gk w*jp a 24$^{\circ}\,C$ room. What is the temperature inside the freezer?    $K$

  A restaurant refrigerator has a coefficient of perfown.azrysn8p+n(6z q + rmance of 5.0. If the temperat8 sqznparn(z. +wy6+ nure in the kitchen outside the refrigerator is 29$^{\circ}\,C$, what is the lowest temperature that could be obtained inside the refrigerator if it were ideal?    $^{\circ}\,C$

  A heat pump is used to keepo e4 *k )-msfinlza+bpm7.8r whmm5/ov,s h n: 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 0 ws*cl;h-fh.b: zvf4 l$^{\circ}\,C$ 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 were possible+v)a.n(nqpi 6o dks r1 to run it backward k.r6n v p+dqs(na)1o ias a heat pump, what would be its coefficient of performance?   

  What is the change in entropy of 250 g of s0d oj, egt o +hcg4otf-/s1i;hteam at 100$^{\circ}\,C$ when it is condensed to water at 100$^{\circ}\,C$?    $J/K$

  One kilogram of water l9+ eea6 vau.lis heated from 0$^{\circ}\,C$ to 100°C. Estimate the change in entropy of the water.    $J/K$

  What is the change in entropy of da y6 1 efc4:2o;mnaum$1\,m^3$ 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 dzshnzo *.ox 0)yp,w+ an initial 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 before striking the ground and coming)y7)bmyxwm) )nzzv 6i to rest.w6y)bxzzvi 7)mm) )y n What is the total change in entropy of the rock plus environment as a result of this collision?

  An aluminum rod cond lepsjh-i*z/rg(esr b- iag8hf8/n2t, 9 9ca xucts $7.50\,cal/s$ 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 3(o /vw()jn2)yydkoq l0$^{\circ}\,C$ 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 at 30dmsj,3nl (w6l $^{\circ}\,C$ 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 650 K p r2nj(x; :x 8dfbxk2:f:xq craroduces 550 J of work ;:f8:x xc xj2xkdfr:(br2 nqa per cycle for 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 probabilities, when you throwj f0 gpno:8wj8 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 -gla+*1bl 4rj qc dck5probability: (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-value cards. Discuss your ranking in t *l g+q4 c-barkd1jcl5erms of microstates and macrostates.

  Suppose that you repeatedly shake six coins in your hand and drop them on theoyim w;w,;dr nje2n+- (dymj3 floor. Con,;miy(ynw om+ d;e3w2jrdn- j struct a table showing the number 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. 15–2 40r) ;pnzhq-bymrgx76) can 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 nex )qpzh;rymg 7n0br -4eds of a 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 use during ln b+fnx2 9k :wiv3w3yvyb-ccc 5je 9/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 /+v9ynk5nljccwiy3f2xce b:9 3vw-b 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. j ycx:cl.qr*09 cqe:g/(mcuq15–27). The water depth is 4*c 09:exrmyj:gcq( uqlcc.q/ 5 m at the 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 ank7u-2h nms.g)t;p eov d built an 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 energy at 215 K. Is there anything fishy about;k u2 .g7mt nhvsoep-) 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 o7ih*qeur t9.efficiency of 0.25 and delivers 220 J of work per cycle per cylinder. When the engine fires at 45 cycles per seconduo i.h9t*r e7q,
(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 fro ulh ev56db 3ic/vu46.o6m.erva2ptbm the freezer compartment at a tev5.e p ectd2uv6abrhv6uo 3 ./mbl64imperature 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:e9nd8oadf l q z,8)db /:mvcg that made use of the temperature difference between water at the surface of the ocean and that several hundreddegz :,q:ma bl) do /8fc9vn8d 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 oppositeq hham35q6dqu m 4wj7ta51q3d directions when they collide and are brought to rest. Estimate the change in entropy of the mhq53ta35a4dudq71qwmj 6qhuniverse as a result of this collision. Assume $T\,=\,20^{\circ}\,C$    $J/K$

  A 120-g insulated aluminum ;a xc *in ;r 2uu+rwjlj3o7iw;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 coef y, jom38 q3w6lp9mr l/b)lasc6aaei:ficient of performance of an ideal heat pump that extracts heat from ame)soaacl3pm: 8,b 3qlw9y/r 6j 6il6$^{\circ}\,C$ 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 relezo xz0+r2bu tjx 1m;8pases 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 operatin1h+gbw ;bdwu:g 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 t og8h nrqxw2-8o state C in Fig. 15–28 for each of the following processes: (a) ADC, (b) ABC,8r8w- n g2hxqo and (c) AC directly.

  A 33% efficient power plant puts out 850b y/-nx-vyj a: MW of electrical power. Cooling towers are jv-b/xayn - :yused 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 at 980 MW using steam turbinga dw8+2,4ytf inygdm.:oy/oes. The steam goes into the turbines superheated at 625 K and deposits its unused heat in river water at 2852.w y/oon+ fmad,y8y :gt4d ig K. Assume that 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% efficis)r7yk ck z7:hw6yf 9dency. Assume the engine’s water temperatuks:h fw7d 67r z9)cykyre 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 jar of cross-sectionav*g/5 -j+2;s0y tfslrrb wodn l 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 abr+t o r (3.qyap)tycwj969vudout $ 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 teo9f ac w5n9s,kmperature 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 “wtjf0/a,pozu4;jhuf:-s:g z refrigerator with an open door.” 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. Inzwj:ao, g:u s 04ujzf ;t/hfp- 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 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