Which has more atoms: 1 kggw))uh3r l5 c yx.g2nt of iron or 1 kg of aluminum? See the periodic table or Appendt xwhyl3u )25)ngrcg.ix B.

Name several properties of materiaoy7j2*zvo) z;yfzbn5 ls that could be exploited to make a thermomete yvz nj)zo7fy25*;b zor.

Which is larger, 1 C0uytkhu*uj;1r xo 3+zu5zd v) $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal eq,u2raqub2i r+7ik2* xchjhl1 uilibrium with system B, but B is not in thermal equilibrium with system C, what can you say abohh2q1+rbcujk 7 22ai rl,xi u*ut the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of irnlgn(fe 1. hub 8dkp0/;-81mhdp xnaaon. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hint:(empl-0d1g 1dhnbk fnx n 8;h8 .apua/ See Table 13–1.] Why?

In the relation $\Delta$L = $\alpha$ $L_0$ $\Delta$T, should $L_0$ be the initial length, the final length, or does it matter? Explain.

The units for the coefficient of linear 1 w)fkgvt-g)ewc) 6xyexpansion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple thermostat used to c cwc+ex6 q/9ewontrol a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both coce9q/+ ew c6xwntact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that a8xq*;xeicub . roa2o-re fixed at the ends often have a section in the shape of a U. Why?8o b.xu *q;ec 2oaxri-

A flat, uniform cylinder of lead floats ikctkop*+ode4 cp-9al3 k .g 5z2avk x;n mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is first placed in a hot tub of waterfkjfyde6:fjt c yi/f3p+ 5ia 2:iu/u*, the mercury initially descends a bit ancf*/yy5 jjpi+6a/ :d3f uft2ui e:kf id then rises. Explain.

A glass container may break if one part of it is he z(:h0xi tby1nfef)/6) upkgtated or cooled more rapidly than adjacentefpx)hk6 (1i/ zbngtu f0 ):yt parts. Explain.

The principal virtue of Pyrex glass is that its coefficient of line3)m84 l.w*ik gw3sx n gohhxg9ar expansion is much smaller than that for ordinary glass (Table 13–1).hsk)3wh gnxmgixg. 943 l wo*8 Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accuratej9)w.glr rj/i at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and top to bulge so badly the cn z61.),eqq9boarb bg*z wmn -an will n mbqb1 ) ,r a6b-nzn9eoq.*wzgot stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its temuxj g4xmnd238*/e; wfwza q9tm *vwy/perature increases. When yxqwnw wxzm8m4a2f3v/ u*9/g;j *det a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged in water increasm)3- tugu. tcde or decrease if th3-cu t gu.md)te temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from lv s, ph7lg7h 7hramlah, a)(jf*(f3 r2a2qvk kinetic theory and the relation between average kinetic energy and the absolute temperatr,3 hm7hhl*vvq2 f(2aa fj)rahag 7,ksl p(l7ure.

Explain in words how ( 42kf wvs .a6t)0gusxkp: yqmGay-Lussac’s law follows from kinetic theory.

As you go higher in the Earth’s atmosph3 k)uidlo6/uc)rhe g1 ere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object must havfv j6c:pp dea 4ej4l3(ubd 7c0e to leave thc:af4dp30p veubj d4ec(67 jle Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than wategy v5d,ufy .ae-pgn7+r at room temperature. What can you infer about the molecular properties of one relative to the ovgag -y.+f7den,5uyp ther?

Explain why a hot humid day is far more uncomfortable than a hot dry d-m 2zkrnv1p)hvof,n3;ptn f 0ay at the sah02-fmto1k nfnr,n)ppv3 ;vzme temperature.

Is it possible to boil water at room tempe9u9jzl7+ jcgz-yhm u 7rature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days whene a:3k9+wsqv *-ul1zj j:w 5ixelc0 bw the air temperature is the same but the humidity is different. Which is more dense, the drwk+3vuwc9q-0zlee5l :s jiw* bax1: jy air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an overheated automvxszs3skhe. 2h( h:emcga1))obile enhsza s cxgveshme.1)2 k( :3)hgine.

Why does exhaled air appear as a litie.0w)8uzj0 h +h wuidtle white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4*slob (7 .pg7fnwnx 7y-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the numbemla h *dq9uq;/r in a silver ring of the sd*ma/ lqh;9u qame mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsius scalre rpav1c/qa ms ,vwo8* fd+q- -av*5pe?v/qvpw-ea,ca5* f-* s q od8mr1+pa vr   $^{\circ} $ C
(b) The temperature of the filament in a lightbulb is about 1800 $^{\circ} $ C. What is this on the Fahrenheit scale?    $^{\circ} $ F

  Among the highest and lowesyb yf2u9pq;p1y8:yv rtzk- w)t temperatures recorded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

  (a) 15 $^{\circ} $ below zero on the Celsius scale is what Fahrenheit temperature?    $^{\circ} $ F
(b) 15 $^{\circ} $ below zero on the Fahrenheit scale is what Celsius temperature?   $^{\circ} $ C

  In an alcohol-in-glass thermometer, the alcohol column has length)yfy x 8jk8ef/ 11.82 cm at 0.8kfxj8 y/f e)y0 $^{\circ} $ C and length 22.85 cm at 100.0 $^{\circ} $ C. What is the temperature if the column has length
(a) 16.70 cm,    $^{\circ} $ C
(b) 20.50 cm?    $^{\circ} $ C

  A concrete highway is buxdz)tw8vi1yprex :7)t5 09c 9mxrecoilt of slabs 12 m long (20 $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

  Super Inva$^{TM}$, an alloy of iron and nickel, is a strong material with a very low coefficient of linear expansion [0.2$ \times10^{ -6}$(C?)$^{-1}$]
A 2.0-m-long tabletop made of this alloy is used for sensitive laser measurements where extremely high tolerances are required. How much will this table expand along its length if the temperature increases 5.0 $^{\circ} $ C? Compare to tabletops made of steel.   $ \times10^{-6 }$ m    $ \times10^{-4 }$ m

  The Eiffel Tower (Figjs 4mcnd3 )3chsl.yu 3iy ;7 fo7s boywsgk507. 13–29) is built of wrought iron approximately 300 m tall. Estimate how much its height changes between July (average tem;k 3s i4yfj0o y5swc7l3 3hy)gncss 7odm7u.bperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, riv((u, 0u5qipdze8f;7eyn mzd lkhcsq5al3 l+ (ets that are larger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is uipu(h ylz+z cle; nq 85l(0kms, 57edfq3d(ato be placed in a hole 1.869 cm in diameter at 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water at 9o8r 7q nvk,ws4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What t09 z yrfwn3,wkt 4xq1will be its change in volume if it is heated ,4txtrnq0yww z 3k91ffrom 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 31;ozlzwd*u 2j50.0 mL of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 5/ d ln0yvb-944wbukz0v yy i52 o9izng5.50 mL of water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to be xx7gy 2:fqpl;placed in a ring made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contain uio7uc fu q4 g0k.s,);pk.9bsvb) hmsed in a long, narrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linea. )skf4) g7uskuc0o;sb,phqu9b vim .r expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the *txuud6d)g,k ocz eh2;0 ,cyydensity $\rho$ of a substance, when the temperature changes by $\Delta$T is given by $\rho$ = -$\beta$$\rho$$\Delta$T
(b) What is the fractional change in density of a lead sphere whose temperature decreases from 25 $^{\circ} $ C to -40 $^{\circ} $ C？

A uniform rectangular plate of length l and width w has coefficient2g,3tgcimzs 6peg2 l :t9rbi j5di -+e of linear expansionigel 6:z dtb2c9p si3,5-j+gr m2i teg $\alpha$ Show that, if we neglect very small quantities, the change in area of the plate due to a temperature change $\Delta$T is $\Delta$A = 2$\alpha l w$$\Delta$T See Fig. 13–30.

Show that for an isotropic so5mkjh+yr59msxkqsi- d:d ar /klu7++lid, $\beta$ = 3$\alpha$ if the amount of expansion is small. $\beta$ and $\alpha$ are the coefficients of volume and linear expansion, respectively. [Hint: Consider a cubical solid, and neglect very small quantities. See also Problem 18 and Fig. 13–30.]

  The pendulum in a grandfather clock is made oz, owyvu j,p3wb d-71n ks*wu4f brass and keeps perfect time at 17 wdw3s1 bjpvuo7zk, *,4uw-y n$^{\circ} $ C. How much time is gained or lost in a year if the clock is kept at 25 $^{\circ} $ C? (Assume the frequency dependence on length for a simple pendulum applies.)$\approx$    min(Round to the nearest integer)

  (a) The tube of a mercury thermometer has an inside diameter ova+g6amy m u, xc9.f7(,7u vrvu(cbgjf 0.140 mm. The bulb has a volume of aug a .,g+9( ,v v77mj(yfm6bcvuru xc0.255 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylindrical wheel 4r kpo-nrbdoi(du4 65n4kb4n of radius 0.41 m is rotating about its axle on frictionless bearings with angular vek4dor(4no4b p4nk ndb5-ri6ulocity $\omega$ = 32.8 rad/s If its temperature is now raised from 20.0 $^{\circ} $ C to 75.0 $^{\circ} $ C, what is the fractional change in $\omega$?   

  An aluminum bar has the desired length when at 15°C. How much stress is wr e7a1ase rvp x152 zp 4++xxa)v7cplrequired to 452)ca 1rpwlzs +vepv 7xepr1a 7+xx akeep it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional area 0.s7czfho34a,jug 0ly5041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 1w rfza:t7s5,fyg )4zc34.122 cm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on theahbxvo3 0;a.utd 7a1r Kelvin scale:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temperature on the Fahrenheit scale;fc7. )1qatqzu s x9sa?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are about ozlhpmm/:0 o) 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

  If 3 $m^2$ of a gas initially at STP is placed under a pressure of 3.20 atm, the temperature of the gas rises to 38.0$^{\circ} $ C. What is the volume?    $m^3$

  In an internal combus 14y6e ngnl93uwa/nhntion engine, air at atmospheric pressure and a temperature o 16annnel43 nyh/g 9wuf about 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at STP using the8c-qu xi h 8qxp3puqivl,8*9q ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitfa lqro c-9iy,+l1 xg)rogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.5 kg of nitrogen ( m spt2)5v dbq)x/p8vy$N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of heliumfw2:rcl1xzu (psln:u;pk- qv4sqj1 ) gas is at 10.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure95a friku;t5vg re1g mec.g+; inside a 35.0-L container holding 105.0 kg of argon gas at 385 a ei5mcu9 +gv5.trk; g;fr1geK?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg of ezhlbyy)mpe1 4v;x2(2 np/ m i$O_2$ gas at a gauge pressure of 8.70 atm. If the oxygen is replaced by helium, how many kilograms of the latter will be needed to produce a gauge pressure of 7.00 atm?    kg He

  A hot-air balloon achieves its bah j kwr v0mi4vjja0p8,c;)j)uoyant lift by heating the air inside the balloon, which makes it less )jj)vrc0h4jiwvm a,; 8p0 akjdense than the air outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air al7 1sjt,mavg)6rkym zxi 9 12vt 15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at xrw+ iayt7h *;7+rhp zwvt91v 18.0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escad3na * z5 rxci iacvhy12t+,0apes a child’s hand at sea level and 20.0 $^{\circ} $ C. When it reaches an altitude of 3000 m, where the temperature is 5.0 $^{\circ} $ C and the pressure is only 0.70 atm, how will its volume compare to that at sea level?    times the original volume

  Calculate the number of molecule86w wkzsbi:vss(x t ,,s / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.04t gsqh p( o2;/veqw2tg-,g66 fjkfgv00 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) mole ,,kok 8p;+qye8-qgtjevauz 2s,    $ \times10^{22 }$ moles and (b) molecules of water in all the Earth’s oceans. Assume water covers 75% of the Earth to an average depth of 3 km. $\approx$    $ \times10^{46 }$ molecules

  A cubic box of volume e d.4m.ffyaj r ri;+c:5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-jw82) wt1ypvvi pla(7 L breath you inhale that were also in the last breath Galileo took. [Hint: Ass8(lppaw 7ytw )vvj1 2iume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxys+0pl l obb5 z/8v c0em)y0a3y ,oxlwzgen molecule at STP? +0o3/),5 y o c wll0lez8smpy0bvabzx    $ \times10^{-21 }$ J
(b) What is the total translational kinetic energy of 2.0 mol of $O_2$ molecules at 20 $^{\circ} $ C?   $ \times10^{3 }$ J

  Calculate the rms speed of helium atoms near the surface of thz+c:0krftryu-w2/ww*j lab kk *.ax1e Sun at a temperature ork kwj*yfakw.:+ t0 zulxrba 2c1-w*/f about 6000 K.    m/s

  By what factor will the rms k+1+vj5xgn / zpoein6speed of gas molecules increase if the temperature is increased from g+5eznxko+6 pn/iv1j 0 $^{\circ} $ C to 100 $^{\circ} $ C?   

  A gas is at 20 $^{\circ} $ C. To what temperature must it be raised to double the rms speed of its molecules?    $^{\circ} $ C

  Twelve molecules have the following speeds vu;in wkj9zhu85s); c, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, u;z89j vhusi)c;wk5n and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a yp sd-4jg z wdsh)dx;04:vr m-gas at 20.0 $^{\circ} $ C is to be increased by 1.0%. To what temperature must it be raised?    $^{\circ} $ C

  If the pressure of a gas is doubled while i d(aa:rx:n+dx ts volume is held constant, by what fact:+an xx(:dardor does $v_{rms}$ change?   

Show that the rms sp-w:alz,fx*- vlr,mp .dxzp, hab9tb* eed of molecules in a gas is given by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two gases at the same temperature, the rat 0j0xjyec/e1yio of their rms speeds is equal to the inverse jyec ej x/1y00ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogenedl;v eo) )dy5 molecules contained in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygen molecule at qw9 b50uky9ea0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average dist-wn8 vg056uf s2uk iylance between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whos ju)vs w4q*mpwd8kk5euu4 )l63h 9 vuie molecular mass is 89 u in a living celkuw vvumwp*3i4h8k5se 9u jq4)ud6)ll at 37 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a gas cspvepe)f 8q(sfl6y) 3an be written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of urazijgn.l is:94nium, $^{235}$U and $^{238}$U (the superscripts refer to their atomic mass), can be separated by a gas-diffusion process by combining them with fluorine to make the gaseous compound UF$_6$ Calculate the ratio of the rms speeds of these molecules for the two isotopes, at constant T.   

(a) At atmospheric pressure, in what pa/,n qrypcic.;tyay7*4dn ; rhases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure i h;3klw82qoir6z.c vms 0.01 atm and the temperature is (a) 9 z8rqo6l;vc mhw .k23i0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a day when th1xdcw7qdzvm3w+ ig1c39 pne2:x 6gthe temperature vdwg+ twmc9 dp6zeg273: 31ih1qxcnxis 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a pla4jlowo((y0lwhsz-e 9 n n5hv:ce where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72zmcawy x3.z:jb6+uy + atm, estimate the temperaturec3zy+.6 uw bjym +:zxa at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of watesq5hpdt) a //3r,,; hanerr9r8akfikr is 530 Pa and the relative p/ a q9d rhhe8;rr,i53kf)tr/aa, kns humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day whqwz0r)th;0w oa :3 cvh th+:gwen the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water is boitl5g*5i uls/wling at a temperature of 120 tlguli*5w/s5 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a +,h0s)ijeat1o3a m4zkm v+ au room of volume 680$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its deo):n/.j hr l9yzl9sdh w point of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine molecule (see Table 13–4) to diffuse a l2ovy,yyvjc++k90 xzdistance of 15 +09lvc o+2vyk,xyyjz$\mu m$ in water at 20$^{\circ} $ C if its concentration varies over that distance from 1 mol/$m^3$ to 0.4 mol/$m^3$ Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u. t $\approx$    s ([color=rgba(0, 0, 0, 0.85)]Round to one decimal places) $v_{diffuse}$    $ \times10^{ -5}$ m/s
$v_{rms}$    m/s

  Oxygen diffuses from the surface of insects to the interior through tiny e-7xry8 ui -;zw c;oc 6xi4h;j) rpjjqtubes called tracheae. An average trachea is about 2 mm long and has cross-sectional -p 78y6 wq -x);uzh;i c coxerj;i4jjrarea of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been calibrat;17quq r e5pk4xlotzr: xo.ykxiq65+ed at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape meas jjt2y*0-4alkkv xwy+xi o g+-ure has been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room temperature. H (q 5+(k(wcvq/vv c55ud nhyixow much error will be made in a recipe calling for 300 mL of cool water, if the wqvin5xc u(w55/ hkd(q+ cy(vvater and the cup are hot, at 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a heli heumy+fmr e v:hh-s pl um+/;r1sz).(um gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has muyl(ehszh .r)-rv+/;u +1 mmpefh:s decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.1 m, a 3*zjhd t,;b:br176g mzudlomnd hei m6j rm;37 zbgt *,h:dlboud1zght 2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the densi+- bab9y67zoq w/rzieh4)0ba 9d q vqpty of matter is about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best ava 4wlvhfz4 ldcana1;9c x,*fgor,7cg ,ilable vacuum techniques is about1c l, fxv9,gzadhgno * 44fl ,7rwcac; $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fills his lungs to full capacity of 5.5 L when 10 m baat/qde; 2 4ngelow the surface, to what volume would his lungs expandde;4q aat/n2g if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a speed of om+t5y .7/jlttk7 lxhabout 40,000 km htk+xy7ol7 / .j5lttm/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increased from 9+ gt--jpliyw 110$^{\circ} $C to 360$^{\circ} $C while the volume and the number of moles stay constant. By what factor does the pressure change? By what factor does $v_{rms}$ change?$\frac{P_2}{P_1}$ =    $\frac{(v_{rms})_2}{(v_{rms})_1}$ =   

  A house has a volume of 77o1xug9lf/0 9af g6p o big11, ckea.nn0m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at the stdj76 ;mqo5dtbn: v,5r n m-uhurface of the Earth, estimate the, r5qd-du h7jnbn o:v6;t m5mt total number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained 2;tf,xr (pqk1b nax c7in a 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygendw)ym6)3z juy used in a hospital has gauge pressure = 2000 psi (13,8d uw)j3m6 )yyz00 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats q t)xx0zgtlc. w9s lvmpt-+-(;g ad:f in a bowl of liquid mercury at 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasoline lpz57ma e 4) pqslzn9;j0ml n-8cjk2lat 0$^{\circ} $C is 0.68$ \times10^{3 }kg/m^3$ What is the density on a hot day, when the temperature is 38$^{\circ} $C?    kg/$m^3$
What is the percentage change?    %

  If a steel band were y1 qla +o27pfjto fit snugly around the Earth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto a glassrf chftlz9t blqk14 :+ )8*hft jar at 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length stadpxuw7q) ad6 2ndard, adopted in the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully charged, has a pri*-obe mo-u2g5cjf z.gfqo k5w ,e a3-essure of 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from thgqxr7.* i/cvry c(96sn u pdw;e Earth is $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennis balls t .tn z(mn9 gydqbwy, go:xg+2(r)mfl )hrown vertically upward at it. How many tennis)r ggy2f)(+mlxo9 d , q.bygnwzn:mt( balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-ck p,zbt3j j h:b:nzsfe0/pa;+m-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfehkn /j: ba0,z+bpez jf3ps:;tct gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on rtx1x6mi s 9zplgo-d, 7f0eq)the following two days: - d rxeoz1spt,g 607mq)xli f9
(a) a hot summer day, with the temperature 30$^{\circ} $C and the relative humidity at 40%;    Pa
(b) a cold winter day, with the temperature 5$^{\circ} $C and the relative humidity at 80%.    Pa

  A sauna has 7$m^3$ of air volume, and the temperature is 90$^{\circ} $C. The air is perfectly dry. How much water (in kg) should be evaporated if we want to increase the relative humidity from 0% to 10%? (See Table 13–3.)    kg

  Estimate the percent difference in the density of iron at STP, and wd t-sru4wn9* chen it is a solid deep in the Earth where the temperature is 2c4su-rw*9nt d 000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, for an ideal gas at 2s 7:fla)sqso constant pressure, the coeffqsf 2l7oass:) icient of volume expansion is equal to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.

  In humid climates, people constantly dehumidwalh) pz qz5y:j y25 -hne(we(ify their cellars to prevent rot and mi(yn-hal( zwewqejhzp5y : 2)5ldew. If the cellar in a house (kept at 20$^{\circ} $C) has 95 $m^2$ of floor space and a ceiling height of 2.8 m, what is the mass of water that must be removed from it to drop the humidity from 95% to a more reasonable 30%?    kg