Which has more atoms: 1()rykgt io 5.x ;ydwo4 kg of iron or 1 kg of aluminum? See the periodic table or Appw4 t5(y.;rgxoi yok d)endix B.

Name several properties of materials that could be exploited to mak/a+r238udv)9cjk(pa*(c flzj i fj d ce a thermometer.9/8lv2)(fjr pafd*d+cjkccuj i za(3

Which is larger, 1 Cpvq 5x9c; 1 c qcklq94c caf80-,iijbd $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in thermaja6f v0rupggi8-)1. ey4 yfz w v;wc*yl equilibrium wipfu0 ywrw -eja. 14*cy )vvygzfg; 68ith system C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip ;9b35dft0m) zpus/w.q o yubq of iron. When heated, the striom) sqt up3;0 bbfudqw.z 9/y5p will bend. Which metal will be on the outside of the curve? [Hint: 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 eg m+ayeii5 3 aqjgqvm;o5(7x7 xpansion $\alpha$ 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 uc n cg2i zzee,vc6qi:)-mo lb/k(;e i1sed to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together n i;(ez)cqi kcb/gom,e-z1:26liv ce. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that ,cq :sy faer;4 0l:hg(ij6ouyare fixed at the ends often have a section in the shape of a U. y6(ue c4h:oj lr:yq i;,sgfa0Why?

A flat, uniform cylinder of lead floatk9d2-c5cqk(r:ky( xbd 1;+qx z ibxmf s in mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass s8;xps *(/gu.xjet9kv x uf 9qthermometer is first placed in a hot tub of water, the mercury initially descends a bit and t9gxuk qpx8* uevjx st9.(/fs ;hen rises. Explain.

A glass container may break if one part bs3w 43m4a h) ifueqmss:j;2j of it is heated or cooled more rapidly than as s 4f;wb3 qe3ujas ):hmj2m4idjacent parts. Explain.

The principal virtue of rsh,. p6k bkb7Pyrex glass is that its coefficient of linear expansion is much sm7rbb. s6pkk,haller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate aq0 bot, q.ubd*skh1k1 t 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 mov)5r0a yu) k+e6-ef8ylmh g0d 63v4 dvdqzcbulge so badly the can will not stand up. ydq)6+e 5hmlk04e3za 6yuf)gdvmd r8c0 v-ov What has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its temperafju3fi fnudl)v8+1aq1 )0k baa rr:n3 ture increases. When 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 striu)uv+l r)f13nr3i1a:dakja nf8fb 0 qke the moving piston.

Will the buoyant force on an aluminum sphere subvq 8 p,u/+stxgmerged in water increase or decrease if /qp+ 8gtusxv,the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Cx vkg3w*o9n3kharles’s law follows from kinetic theory and the relation between average ki3kwo3*xvngk 9 netic energy and the absolute temperature.

Explain in words how Gay-Luss9z /o s -f8v1m:6fd)elwte sgsac’s law follows from kinetic theory.

As you go higher in the Earth’s atmosphere, the r(joflhi(+.,sl vb*x l +smgd7 f 0l-nqatio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth xpnir4; v )aqs4q8v(m oj58 lkrefers to the minimum speed an object must have to leave the Earth and never return. The escape velocity for the Moon is aa)5s 4x joqk;v8m8 p4nlqvr( ibout 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 water at room i0ldu k6v)5v ktemperature. What can you infer about the molecular propertieku)d i0v l5kv6s of one relative to the other?

Explain why a hot humid day is far more uncomfor prgev. m1r myi1ram4k4*+ uov6at :j:table than a hot dry day at the same temm *kpvr1a g a6:ymru o1v:j.i +t4r4emperature.

Is it possible to boil water at roz:bln89e1,ek8 5 xnzkrgs-ixm ; d 0jvom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is theikw.cf:t z61nfe6+bhc2 xi(t same but the humidity is different. Which is more dense, the dry air or the humid air at the same f+i2 t6hccw.(e:nikftbx16z T? Explain.

Explain why it is dangerous to open thk(,;6btr rtybsjk h6 5e radiator cap of an overheated automobile s6b(5bj r6,ttkrk y;h engine.

Why does exhaled air appear as a little white cloumg y/5- 1bdkvguokm(/d in the winter (Fig. 13–28)?

  How many atoms are th(t7v 1jfc.h*rjd8mb2 q k nj(xere in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of bd o8ltuep4m o9b;1e5 atoms in a 26.5-gram gold ring compare to the number in a silver rimb ot9e18d;o5pe4b lung of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is oftvv kkll /jxac1a)7 7*ten taken to be 68°F. What is this on the Celsius scale?7*ac/7 1kl)xvjav ltk   $^{\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 lowest temperaturesx igm;* kj/joch kxp1h46r*8y 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 col9,lwr3 kr/n.pmh u o2d xy(lb,umn has length 11.82 cm at 0.0pybu 9, l h2/nr.dxlrmw,3ok( $^{\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 built of slabs 12 m long (20 irq -i, qpzwy v -g2m*84vwjey, h)db;$^{\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 (Fig. 13–29) is built of wrought iron approximately 3 pz 96wc;k jdht/6s,l)2hd fhr00 m tall. Estimate how much its height change/w rjd6hszh kpd) c;fh 926l,ts between July (average temperature 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, rivets that are larger thg w0s)z.p0bhq vrt g+: tt7xn5an the rivet hole are often used and the rivet is cooled (usually pvgtw+nt bgz0s5 tqr. 0hx:7 )in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to 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 tt,6:rxej l4 j(uqel3vs4 5jnat 4 $^{\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 diameterft9 xs 74j*sq4h( jnfr. What will be its change in volume if it is heated from 30 4fj*4 9shfqr st7 nj(x$^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL d8bxbkm/8/w +/o otfhof 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 55.50 ghtrlwm3/ ) i5mL 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 placed in a ring made of i82 ulkg o()ussow-i6 gron. 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 contained in a long, narrow vessel so it cbj(4yx+ t; lj 0.ujouaan expand in essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to theb.t4jaxuo y+;0uj lj ( coefficient of volume expansion $\beta$.

(a) Show that the change in the spi i,ic9nnef+a r*0,density $\rho$ 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 coefficient of linz; xi f8i719ba5tthj zear expx bia;1j 5zih7t8ft z9ansion $\alpha$ 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 isotropion n:f1efs5+e vrgc/g(4a1pk c solid, $\beta$ = 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 grandfapz6 ( aqxe4ln .d9-swather clock is made of brass and keeps perfect time at 17(6d94les .px z-nqwaa $^{\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 merhc9onb x-x oqh,u6;2s6dv, afcury thermometer has an inside diameter of 0.140 mm. The bulb has a volum9n6v,;hfbxuxo q6,dha s 2oc-e of 0.255 $cm^3$ 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 of radius 0.41 m is rotating about iuxmm-60jlo i; 1aw;bc h 2fnl:ts axle on frict;;62mfljmnh- i ulcxbw :1o0 aionless bearings with angular velocity $\omega$ = 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 whe*iyt:bl bn-/b x5uin-tvv) 6 un at 15°C. How much stress is required to keeb -bivb/n-ytxnv)i:tu65lu *p it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-l.xzkg- n +oe* 6a:*vkjibx)fbeam of cross-sectional area 0.041$m^2$ 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 134.12fz wzvj3*xm/:etv2iw; b1b z12 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 tfhwnh iud8- w0 +u,si0ni09easbi 35 jhe 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 temperatu+zelp t, ifz:;,8 avrnre on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth andarr6bj 87/w *-mb,u- sov 5rw6vr)hwgr fm/go Sun are about 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 combustion engine, air at atmosphericz5+n;7r/oxv pdv9g: gk uu1mp pressure and a temperature of abouxr1+ p; gn7vpd5/9ou :zu vkmgt 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 usi*twz;wlz v5;fno o;1 ing the ideal gas law.    kg/$m^3$

  A storage tank containsi-qk4z*xs ek) 21.6 kg of nitrogen ($N_2$) 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 m46.x) bdt0y ge 9jrreqj,24k s5 pknlof nitrogen ($N_2$)
(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 helium gas is 0n ll(mid hsmhdzp2p s79k2wno9*i 86at 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 pressure insi16 aah0 mr6fb 3f ,gzs4i5brside a 35.0-L container holding 105.0 kg of argon gas at 385 i6m4gff6s5sa b1i hz3,brar0 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 k-ky k1 xn9t+,g7jx5v-yv ibd dg of $O_2$ 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 buoyant lif43) w/by+ ivt2dy c s2daip fov3(lk0rt by heating the air inside the balloon, which makes it less dense than the air outside. Suppose the volume s2 3 air(ctbil) y v3ydv k024+fdp/owof 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 atd*v z(ss3 un2+zf 1e r/ffr 7.hjb7bey+qtox 5 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 kfb hf :3ffh6q7s(dxcnqpq:j3tz3:*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 balloqtt .u7j.vqv3tegnudg8-0qv 2t k-7r on escapes 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 mok* v7 il8*zebplecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.00 blhh;nqql8t;q2)9n k0 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) moley:ctoy x/e +w-t ,z(kds,    $ \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 volumegjmm:r( 4fx ) w*mnc9y 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 h48uef)cj*e *6s qipsof air are in each 2.0-L breath you inhale that were also in the last breath Galilu hs)eiqscep* *fj684 eo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of anzdriirvlx ;) 7g82j f-vv;1kq oxygen molecule at STP? 1j ;gixdv)i7vr2zq8-r; lvkf    $ \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 su1zgm)qeqc bh6 b1pfbe7q(k g 1b6 xw1*rface of the Sun at a temperature of about 661qxem kez1hg1p b qcf q 7)*b1(g6bbw000 K.    m/s

  By what factor will the rms speed of gas molecules increaseqed/7n sxch0hri9f k. .ky wm e*ku,53 if the temperature is increased freyx.h/e7r5u wmic. kkq n90,* sf3khdom 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, given in units of km/s: 6,( em 7ujs;6w9qv 8ammn 2, 4, 6, 0, 4, 1, 8 wu79mq sj6v;(mn ma8e, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecjeh8y 5ntf49utwh /4eules in a 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 ga;v q)zi3wp)wql tw70hs is doubled while its volume is held constant, by what factor doeqzw q)lh7 )0twiw3 pv;s $v_{rms}$ change?   

Show that the rms speed of molecules .s.jik;hk7. jq13rfoot d v emh,; b+din 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 gar/w bjr4.ii g4j2 ms4yses at the same temperature, the ratio of their rms speeds is equi42jb/iryrj4 4 s. mwgal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molzswoq (/*x ok2ecules 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 speq p;)vj6ki nk3sxg18ted of an oxygen molecule at 0 $^{\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 distance between nitrogen molecules awlzx7q4qcu 62 t STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid wrhl*-g p9wymmuc3+ 9ohose molecular mass is 89 u in a living cell -ryhgu39o9mpm lc+ w*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 gat 1o -jjqlg6f,s can 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 uraniqg xehqil3in6)5 k;gp t0 )n(gum, $^{235}$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 phases c+f()ounv7*6x 0r ko tn;uaw ulan $CO_2$ 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 p-o94rd3 a3ndrn1 xrkwressure is 0.01 atm and the temperature is (a) 90dkd onr3ra rw4-x931 n $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) guzxig ;.)4t oif the humidity is 50% on a day when the temperatureg. z;u tx)4goi is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a i( r.-e os)w3y8iraed7w/n vzplace where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72 atm,.yt5idf ( vsy:5e+gi a estimate the temperaturei:y.ed(av tg yifs+55 at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of wate znrpl 2n/ct ;bgo,y1g48y9xor is 530 Pa and the relative humidity is g94clg ryo,1ox;b yz2n / 8ntp40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the tem);wztdd *1m c rawen47perature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure 9 jcktz2v/q +o9mq1tv-je 0lr cooker if the water is boiling-r9qc1zlt q 0t9v2v/koemj+j at a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a rl:). a- vx(nzmcy.hkl-l0gz 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 dew poidk1t2erd ny a5w4x(4pnt 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 morkikya /z;.- o g1+zxalecule (see Table 13–4) to diffuse a dist +ykxa/.a1krzg i- o;zance of 15 $\mu m$ 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 tinyte a6dtvp/q29 tubes called tracheae. An average trachea is about 2 mm long and has crosstt /2e6qvda p9-sectional area 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 hasgpsaf3o 1 dn9) 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 precise steel tape measuurwqt(5 o7(dm re 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 tempef h+tjh ge:( ao-djy21jm7 5dhrature. How much error will be mad5hj :fhyg m o(-a1h2d+7te jjde in a recipe calling for 300 mL of cool water, if the water 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 hell pa1ga 96sia7ium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gassap9a ig6a71 l remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, wio i.vt 4w;*wubdth 3.1 m, and heigh ;4.*iow wbuvtt 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 density of matter is about o9,;or8sh vo sh;1 mekane 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 j8)7ba bk f050dex z.ls+kq lmusing the best available vacuum techniques is aboujdfa)8z+5 bq0lml07x. se kk bt $10^{-12} N/m^2$ 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 capac;uqto9pyso*4 qr1z/ok2 tp d9ity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he ook utzt9 spr/ 9q4 pq1o2;*dyquickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a spe 9x:x0o2fex 2 o al rgeh;66sj;w)qdgo9c6f rsed of about 40,000 km/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 sph ex9 r;qor ;jo06:dgsf )9x6 a2sofcelw6 x2gecial 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/k4b vnap5 7a mq.xpr3 increased from 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 770 a6ke . +)bpre6fivnh:m$^2$ (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 atmospxan4p8- d rr6gr)gxc aq+ymkn9j:3mk6m r(j ; heric pressure at the surface of the Earth, estimatra3pj qx- (gk n) 6 n6mm+ryrx498mg ad:c;kjre the total number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained in a yd /ysk gjt *l1ugmu d8+;z 32l5q v**wywr+kj7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygen used in a hospit1 (7h fxsdw/ y+bjth97xc e1ntal has gauge pressure = 2000 psi (13,800 kPa) and at T n9 y 7b s/ehjd117xtx(thfc +w= 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 in a bowl of liquid mercuryx-8- o e6zm/vj0n uhau 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 bk aeu.v hw1 oy;-h)./2kkmt 0q,sfbaat 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 to fit snugly around the Eart iq8vj)ot9v4nk,xx/cy 9k2hkh’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 ontob rzsi 99k7p(q (d,ckv vy*x6 bmzs;,jwqk:j 8 a glass 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 standard, adopl2hs;unw)nkp)bts u8+ry;)es-f f .kted 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,6 * o3in*e1rqb6 qtxfi has a pressure 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 the ij l4;aq.x xwq4-hcg;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 t97ou()ykqn ey zz6a;eennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg an7e( u)zyk9e6q ;no yzad are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spc6. 2muipvowjp4hy cz3t r4. 9herical) 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 perfect gas. How large is the bubble when it reaches2c4.9 vi3tz jp hmuyoc46.pwr the surface?    cm

  Calculate the total water vapor pressure sgd.z( 25af9k3z x 5eucfwxy9 in the air on the following two days: 3u5wg99 a2czf5zfks(e xd y .x
(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 when it biy3f3 j82 pyse5nxv7u0 aqn8 is a solid deep in the Earth where the temperature iqe3 0 xsf u8n pyi837bj5na2vys 2000$^{\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 constant pressure, iemc u0 2sk-l*f xs2-ythe coefficient of volume expansion is equal to fm- su-y0x2i*s2cek l $\beta$ = 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 dehumidify their cellz :zih*es v cek51 nivt1o-b94ars to prevent rot and mildew. If the cellar in a* v kce-i1oheniz: vstb5491 z 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