Which has more atoms: 1 kg of iron or 1 kg+uld92r ahl9t of aluminum? See the periodic table or Appendia dhr+9llt92 ux B.

Name several properties of materials that could be exploited to make a thermo3b19l zpe:8mdrerp c hu9v-:fg3m 9 gkmetezm3:hprr cfe de9lg9 -gk 8um9b13 :pvr.

Which is larger, 1 Cln,e0wkp l up0vl.tsv(z (n j.s4c5s: dlq 0q, $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thqtfbc -8k*a0goo o,3n ermal equilibrium with system B, but B is not in thermal equilibrium with k oog b08f q-otac3,*nsystem C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip *9nkgizb308tuy, . gsc g1jjcconsists of aluminum riveted to a strip of iron. When hea, igg1ukcbt8.n*z j0y js9cg3ted, the strip 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 linu.j9 zeaf )eiaea4gf) .y+kl+ear expansion $\alpha$ 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 toi nv 6blcjz*cgvt3r0h ad:lp5- a:.20gn0vrs control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch 5dzglc.6-lvr*tp: g00ah:nvnbic rj s203av 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 are fixe 4avplc e3xrubddyo. hlt)b1l 8;, 91cd at the ends often have a section in the shape of a U. Why l4)d,bcl1cdpxua l8;y oe.h9 1r3bvt?

A flat, uniform cylindr -pd bfags43fj+e w5/er of lead floats 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 thermometer is first placed in a hot rw ,*yu 2:ddql.hcz4 vkdjp5 8tub of water, the mercury84:zydu hq*2ljdd p, 5.rvckw initially descends a bit and then rises. Explain.

A glass container may break if one part of v9 r9bwh3m(yw it is heated or cooled more rapidly than adjacent parts. Explai wmr9wh bv3(9yn.

The principal virtue )ut ;b nat3i2i l6txt/of Pyrex glass is that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives riut) t x/3t6ilb2; tnaise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate 2n;ky s* cnq( 2z+ud pt+zm1t jt /qndw;j0:mqat 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 willmvlpu0i/xf 3* cause its bottom and top to bulge so badly the can will not stand up. What has happeneimxlu/3v* 0 pfd?

When a gas is rapidly compressed (say, by pushin;mjpu62;/ s;li wnlm y j n(h6vzry9c8g down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain thesiyp w9y 6u;6hzj( rm 8n/;nmlj;vs2 cle 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 aw1v) *w;b iqve-p-g rkluminum sphere submerged in water increase or decrease if the temperature is increased from 20 bv;- 1prwqwie)k g*- v$^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’)s+ l 3s4,hr7jxgn npos law follows from kinetic theory and the relation between average kinetic energy and the absolute temperature.,g+jh lr3 soxsn 47)np

Explain in words how Gay-Lussac’s law follows from kinetic thpk37r sx:hy0ciy drf7b1q 6a7eory.

As you go higher in thez*r4qz id6 n e,;)t/;l yrjcr9m,ykzt Earth’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speex sc22hkpw o.n/;oll 2d an object must have to leave ;2hx np2 l/owklo 2.scthe 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 water 3 ijc; bfw:o7sat room temperature. What can you infer about the molecular pc;so:3fjbi7 wroperties of one relative to the other?

Explain why a hot humid day85v 0 hzbq8yyo3z ofl* is far more uncomfortable than a hot dry day at the same tempy5q o3h0 ozz8*bvl8 yferature.

Is it possible to boil water at room temperature (20l5jew8m8 lrub,l-jwb .q .*xj $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humidity isfh8 t5p80 qqgb different. Whichqg8q 8h5ftp0b is more dense, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to ope ,p rnq4 f7ky8rv+8ia60l auwxn the radiator cap of an overheated automobile enrvql8 kw6rap a f,8+xun0 y47igine.

Why does exhaled air appear as a little white cloud in the winter (Fig. 13–28) 3 hmr,ih:h/uy5t nn)s?

  How many atoms are there in a 3.4-gra;ciyg04(t;e62zyi1 uwd uy u qm copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compard37xaudtg) ip) th.ox x99 :bv zcq3e7e to the number in a silver rin9.x z7g3tx)3) hocu :7t idabd9qpex vg of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is thbyg;of my-qn a4uj950is on the Celsius scale?;m95 -uybfn ag4 ojyq0   $^{\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 temperatures recorded are enr 3usgx3 1ru5m1y r2y8d:gx136 $^{\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-glassjxr+x9hsaq vej ;.ab2; .1s ea thermometer, the alcohol column has length 11.82 cm at 0...eaj; e abx;+19qvajxh2 srs0 $^{\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 b ,kpuq /*3muiy,hm*,fif0 zziuilt 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 (Fig. 13–29) is built of wrought iron approximately 300 m/f9m*hm .2hk aq j 3s)xghis,c0nl uy) tall. Estimate how much its height changes between July (average temperature of 25°C) and January (ave* mg9i/sfx)clj2n03h h )k,ymqh.asurage 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 lar+*bzd:taz hqm:q/5how vmt2al;z2 t4ger 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 :5ta tmbmwq4 +zq :2ha2/vhzd*o;ztl1.871 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 n,eck1b l at:*at 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 diameter. What will be its h/n 2*e,haqh 7w:u.mgckem/wchange in volume if it is heated from,ngeh:7*2k .h /ham wem/wucq 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the b0tjbg(fl a ;.0yup3zr rim with 350.0 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 55.50 mL o- aa17zr0ig o-hsja q1f 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 il3xl( -+dck 8/r mcmbbron. 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 vessel2sggee f5 vzrkr((2 u0 so it can expand in essentially one direction only, show that the ee5gkg2sezru( (f2 rv 0ffective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the chao; 5/3igvutjy nge in the 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 rectangula 0lvn/tfpwha1 wi2wl):pu9- w wgh2y: r plate of length l and width w has coefficient of linear expansgp -i12w hwlp nfww 0t/ly2 awvh9:)u:ion $\alpha$ 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 isotro9o 5/ clvg1huppic 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 grandfathe74jk jgl)*cbz;*m 8tu s2pin gmyd7+jr clock is made of brass and keeps perfect time at 17 *8gmuj7* cn bm; 2 spzjldjk+ )yt7i4g$^{\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 i6tz+nib+prv* c ; w. l0vnohp*nside diameter of 0.140 mm. The bulb has a volume of 0.c+hl *b+w 0orzpvnt 6;nip.*v 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 mp t+ foh 1u01b-p3 kbc(nud8vk is rotating about its axle on frictionless bearings with angular veloci+fp8kb-1ph3ucnbk0uo d1(t v ty $\omega$ = 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 requil8xw mn) (p3p94fii5op;dbi yred to keep it ymxnfdp)ip9l( 5 ;p wi348iboat this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-se6kl y x/l p0g4wgpc)sg-j7je5ctional 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 134.122 cm at 3x )a +j-y tbvph88vrq20$^{\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 d 40tx8q.as , ,zcbuqhthe 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 Fahren9vb+pe6 zzrb684 fgtaheit scale?    $^{\circ} $ F

  Typical temperatures in te0gq ip(yc4bt ),gx f.he interior of the Earth and 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 atmospheric pressure and a temperature,b kn fxivv):85w(qju w.vl u8 o8v )lv.q uin kbvw5w(j,fux8: f 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 the ideal ge0egul kt7+2f d5d tc6as law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitrs,*tq n wvbue*n5 1pj+ogen ($N_2$) 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 ofnnrl :w dv5**f 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 at 1 3a wto2hmyfify+: 95j n+xu3v0.0$^{\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 inside a 35.0-L container holding 105.0 kg of argon gas larh4(mb1dg. at 385 K? .hrm1a(dblg4    $ \times10^{ 8}$Pa

  A tank contains 26.0 zrirzfgoq,d5lr 8 x,v -j:9b(kg 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 achieinr- :h:z8fj yves its buoyant lift by heating the air inside the balloon, which makes it less :-8rz:jnf ihydense 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 a 4hayb1k chx3n7/d qo5t 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 18.03pmap-:)0sp usf ze .u $^{\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 escapes a child’s hand at sea leveld8g m-exq2* vk 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 molecules / 3 zew wa, kpn:;htn3u4$m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many molecule m/ox/vje;cwz jty122;mlt * cs?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) 9y.n)f qyftga 2pi43( ti +q ,hor9mrsmoles,    $ \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 a wuvo2 8,hcg6ro8f-s 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 iju;oxxrs rs74k -*q/k n each 2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of csk/* ;-7 rxkoqxjsu4ronstant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kineo j: y)+j)nsqatic energy of an oxygen molecule at STnq)aojs+)jy : P?    $ \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 the Sun at a tet96xi uj*cgjuqt9z 1+v 7,ctnmperature of about 600v 7j+jztt c1 u6 ui99qtg*,ncx0 K.    m/s

  By what factor will the rms speedip fw-+9zt2 p fwls6+s of gas molecules increase if the temperature is increased from w9 s2f 6-s+piz +ltwpf0 $^{\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 th tp,z ont6;+az5vn/imd 4yh(oe following speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7zot;zi6+t,(ad4om vn h5 /nyp, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas at 20.(9 go aj medp44c+-rxw0 $^{\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 its volume is hr-anzp.l9kudt p l y+)d-v6d;eld constant, by what factor do6r- l.pd9d ;dznu+kpta )-yvl es $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is29duhhtj n bzcjir-/krcww ,8*:*w8z 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 tempe cgcf0/mo) a (gsah55urature, the ratio of their rms speeds is equa0 fhsg55 )c/ua(mga ocl to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules co+u74 j3hpetdmoh6 )/vdvl;i u:pekbf(gf 5 5gntained 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 oxyge +,rh;fic2xec.i8nfb:( aza2c5 ih et n 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 betweew iq8 /xu)3ulkn nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecula+4wt x*3y - dy9mwzrhhr mass is 89 u in a living cell y h dx +yt43m*w-9hwrzat 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 can be writerhtx:zt *3c1 ten 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 ura7 ;41d9nav c hpw3z5b ze6rupxo zr8i)nium, $^{235}$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+tdn k 9,rl:d uzyjj6-5qz xj5bn- ua9, in what phases 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 iq: :0f;fxngm ps 0.01 atm and the temperature is (a) 90 ;:pfxnmg :0qf $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humiditon 2u a/e63xg(akz o71i( lksam,umb8y is 50% on a day when the temperature3za(a bien sko/(o 6,uuaxm72ml18kg is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressu(caw j oy7 xs2+ ;+gwy3r6hyjore at a place where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.e sp: ft3m:pyx:l-6cu72 atm, estimate the 6 pfp:xlmt-ys:3euc: temperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature )mec5j:rj- dtvp-tl6on a day when the partial pressure of water is 530 Pa and the relative humidityct:-je5- tvr6mlp)d j is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of wad o u:*oy,*sbzter on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure e152wd h mlv,8gd9hhdg:0r fhi3f r1 finside a pressure cooker if the water is boiling at a temperaturemr8,hd0fh12 3e 5i:9rw1vghhfl gdd f of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of:fvozlmbby6 a i c1(;/cpz/y) 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 point ofe c jqz1s3u zuh+jq8n4; ku3b1 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 glymkr0jo , 8pa;qcine molecule (see Table 13–4) to diffuse a distance o0rpajk q ;,8omf 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 oonnsn 8li) gp )gpm,5p8s8.n kf insects to the interior through tiny tubes called tracheae. An aver8 gs ko.),5n 8pnn ing)lpp8smage trachea is about 2 mm long and has cross-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 has been calibra*b sf +-gefdfq(d4uc jux9q8j9z1 ag1 ted 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 measure has been calibrated atb;o+if qak yv*ieoo ;pr 7wi c3*5kc*) 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 tmq*xmw ,1g )yl wfo0e1emperature. How much error will be made in a recipe calling forlwyo e w),xq*mg0 1fm1 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 helium gljmrs *8/s t1was cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 *wmt 1slsr8/ jatm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molz787eoh w -mhhu2jf b2ecules in a room of length 6.5 m, width 3.1 m, and height 2.5 mh7w72fmo- b82e hzuh j. 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 oadscf013n(t2w op- a(p bu jro7s- km, p:tec2ne 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 a4;inxx 5mbmiewxlt0t5) 03 rlttainable using the best available vacuum techniques is about )45 bw t5itme ix0l;rxn30lmx $10^{-12} N/m^2$ 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 lungsf8,(dhyk ga h9opw 7t; to full capacity of 5.5 L when 10 m below the surf8g7(aok;yt p , 9hwdhface, to what volume would his lungs expand 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 /o9c49lfbp6upkbx (h2w we:zof 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 ow4b2u (p6:lb/ 9 kfcexpzh9wof 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 isjldy l+m e(59k 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 77,; vrv9qdsx v2pva xtlp32 8a)0m$^2$ (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 surface ofe9s h; 2mrcrum . :sgq8:8kqsk the Earth, estimate the total number of air molecules in 8uqgk:mqssrekmch .s:;r829 the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of1abe6c; tiobt7mr:h k 6,-qf a:1h+ 7ioazyme nitrogen molecules contained in 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 oxygen used in a hospital has gauge pressure = 2000 psi 9a eiggj;qnqso, 1c/6(13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.,ga6iq/c sq;o j9gn1e4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid mer ;;p55dn hg9uvfst x;cl9nyop zvx*p*6cj x 27cury 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 gasoli9vw54)ffluai,h wn6mne at 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 snuglk c obrvge: px8;6b09oy 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 tm ssg-0v 0z 4ru0a(grxightly onto 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, adq,2ev tp wskwzk u5;-5wrt1f.opted 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 char;y2 :in8dddzy ged, 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 Earthruge; xtb7y re rg, 5(+7f(zdp 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 thrown vertd6a6lfrinjs:-( c jf,ically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they ,ijj6(d s- fcla6nr :fhave a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.0y06xceo g9c/ld. y22va4ku lx0-cm-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 perfect gas. How large is the bubyulc9g yla x.d2evo/0 6c 2x4kble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the following two days:nmc )vbz3f9v 1y9w l2k w)c392b kvv9zmnf1yl
(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 differe3kob gfx38.b j(*saoxnce in the density of iron at STP, and when it is a solid deep in the Earth where the temperature is sox*g b3.jk3xb8oa f( 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 prswj57elt4z jj 7)r/ zcessure, the coefficient of volume expansie7lrzctj j)w4/s 5j7z on 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 dehumidify their cellars to prevent rmn 5j mi0rj+v6g8zcs7 ot and mildew.nmr 0 +6simgcv85jzj7 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