Which has more atoms: 1 kg of iron or 1 u3cpr92v z,wz,f8zeaa; rrq5 kg of aluminum? See the periodic table or Appendix 8 cu9ez,prarq3a5w , r f;2zzvB.

Name several properties of materials that tjk4o bzeq b, *hc:)j6could be exploited to make a thermomete4bz, :ek)bqcjh*6o jtr.

Which is larger, 1 C ef(y-8bj f4ajsdr2 ng) l f.1t$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in thuizq. f.mh iuv7* 1d he5l5w u k2rhbyvg)h,7+ermal equilibrium with system C, what can you say about the temperaturvle),fhkz.i*r1y. +muhiw 7b5hq 7 gd 2uhvu5 es of A, B, and C?

A flat bimetallic strip consists of aluminum riveted toyg d:) ua l(moeh ;dw+pl:xm,: a strip of iron. When heated, the strip will bend. Which metal will be on the outside u )ol +::x;lhdye (wp gdm:,amof 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 o ) a+ b9exbll-9++ zciluomhg3f linear 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 gi 8 h(5.ybor63)jzgbpxwbu c ovt1--a simple thermostat used to control a furnace (or other heating or cooling system). The bimetallic strip consists of two-wyb (vxrico5.1 g3g 6z-hubt)8bo jp 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 contact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at the ends often have a section in the shape o eyg :v 9* bf+1t0azk(0zqeexzfy (e1xzb +eve0k t9gz* a0z:fq a U. Why?

A flat, uniform cylinder of lead floats in 1zop 3n 4xkqm0mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glastn4g 0 ftqdr *m/sq+b)b* pu53svy-kx s thermometer is first placed in a hot tub of water, the mercury initially descends a bit and thex/3*pum0yn)b sqtq vg*td -sf k5+4 brn rises. Explain.

A glass container may break if one part of it is heated or cooled more rapidd796k-allr2btqq . mzly than adjacent partl lqaz.dbq2 6k9-m rt7s. Explain.

The principal virtue of Pyrex glass is that its coefficient of linear e ipcmp s+a*e aaxw js,*qg6t. ns394w.xpansion is much smaller than that for ordinary glass (Table 13–1). Explain whyq.s p. +ag,6m9cteawsj3*4aswni*x p this gives rise to the increased heat resistance of Pyrex.

Will a grandfather cwwmuuvi.ec vk/2spr /; 88l6-t)csb llock, accurate 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 can( dskj 8z .2zfkoxdqgtwl5z;c 1:;6es will not stand up. What hasode ; jsqtx8k:(zds26;15g . fzwcz kl happened?

When a gas is rapidly compressed (say, by pushing ./m2 r8h uq 0qxz)qcvkdown a piston), its temperature increases. When a gas expands against a piston, it cools. 02kqq) zcumv qr .h8x/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 wat4fgf7q 0f ej5ier increase or decrease if the tg0ifeqff 547jemperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law followsv19scc)p-jv6p hs r r, from kinetic theory and the relation between average kinetic energy and the a,hvp pvcr 1s)9-r6sjcbsolute temperature.

Explain in words how Gay-Lussac’s labyut, v6dwr-j26ma o q;4+igbw follows from kinetic theory.

As you go higher in the Ear4rc(pb.qij o9th’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum sv7qsz- a:p thjsq:06 opeed an object must have to leave the 7 tosq0z jv:-:pqahs6 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 q uo aa(x7val;5uickly than water at room temperature. What can you infer about the molecular propexa; la5v7 uoa(rties of one relative to the other?

Explain why a hot humid day i6of3h;gtfmq ( u fpx 54yv26avs far more uncomfortable than a hot dry day at the same 5 h mp4vg3f(vxuao26f ; 6qtfytemperature.

Is it possible to boil water at rg(2w gnm z8px+oom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature if mopj;2pfamw8 pzq1s.4 6a* aj97tdms the same but the humidity is different. Which is more dense, the dry air or the s 8a4awmpdp 2q7m 9*zjtopamf.1 6;fjhumid air at the same T? Explain.

Explain why it is dangerous to open tiuvnw:ol w, a(k7f,grg a3i83he radiator cap of an overheated automobile engine (:g raw7vi3fw,,uloaki38n g.

Why does exhaled air appear as a little white cloud in the sj-fgv4f, 69j(uuem pwinter (Fig. 13–28)?

  How many atoms are there in a 3u erct +hoi50qt b/v)4.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring comparexa5cym)l nz 2(421wxh )cppxi to the number in a silver ring of the same mass?m lcp45hw cy xa1zi xpn22x)()$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is ofckts1 vwd drf868n v 3tq;--qtten taken to be 68°F. What is this on the Celsius scale? 8nfrq-ktc3v1t8wd6dt;-v s q   $^{\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 lowes cz r-3tqap91 wr4oj6ht 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 azfxea q7p26l. miefdunk7;m:*m3g y+lcohol column has length 11.82 cm at 0.pmue;2z inlk*6.f7d+:mq7a3 g feymx0 $^{\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 vol;+ cw:;syo$^{\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 jjht+ii,0zfr8d.x4 c wrought iron approximately 300 m tall. Estimate how muc jc8,h0ijiz xtr+fd.4h its height changes 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, rivetsmv-a .g)dxdcua*4 y9g that are larger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placedmyg*vg9 -.)au d a4dxc 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 at,pxwbqac 02xyt41fo 1g0* qqt 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-btoi cyf4;gn+2v) ,hcj73r:i zm8 : apqzdxv.75 cm in diameter. What will be its change in volume if it is heated from 30ipac z+:rf jyco)nmq;h: 43gi 7 x,82vdbv-tz $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL m9g pnvnl kr9j380zzi7o+ k,gg /:gtl 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 mw p+z(pn8:sgoL 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 rin o,mpm3m/6x6ax 6n3g- bgeonhg 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 contained i : 6sjkbxzp9/7wkrzg 0n a long, narrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to the coerzsx06k: zp bk7w 9/gjfficient of volume expansion $\beta$.

(a) Show that the change in the deicv/ 1pit d()ensity $\rho$ 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 lengtuk,)h .bytgg2 3.piluh l and width w has coefficient of linear expgb pi)hu.2l3gu ky, t.ansion $\alpha$ 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 soidl.df9a pgumpf8fd* p),e1; 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 of brass and keeps perfect time aa.vi hfzw1jv8;:fp5x fwg3gml- 3w2fm /wj9zt 1f59 zfm wlg2wf-f.j/ zpix; w1a wmv:38hv g3j7 $^{\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 (; ayb,f zi*p6i.hqd sinside diameter of 0.140 mm. The bulb has a ;,s*hiz .if (abp6dq yvolume 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*3vyywq :1)qj r/:vpdzg6 tvj radius 0.41 m is rotating about its axle on frictionless jpq31gd) :*qwzvtyr:jv /vy 6bearings 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 when at 15°C. How much stressakir 9* y81og6zw;pgk is required to keep it at thik* gor6ya ig;p8zk19ws length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectix.;z sybr5.hconal 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 i:mmt;/9niy68bjmq.hi1 uce 134.122 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 the Kelvkp(r z+cv 2 16qnw du:ghs:ixmh wf5 a:)7aqa2in 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? 43f umsprt. 7w   $^{\circ} $ F

  Typical temperatures in the interior of a7fh1 x-47m xutxjtt,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 engin7t g7atlr2leg g5j(k/g ru1iya j3i ; b46a-jte, air at atmospheric pressure and a temperature of abt( ji7b6yk4agt71jagjea 5rg2l u/l gr-t3;iout 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 thdg;xzn)y,xj0 uqix rlb q9 k 9);x47dce ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg),+sjxevi +ku 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+j0cj1-);dytepte ;*c rhedy contains 18.5 kg of 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 gt,w+5ei: ebt 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 pressure inside a 35.0-L container holding 105.0 kg of argon gtz ntdpy-et+*: pa. 3uas at 385 Kte* :t npa-y+3.udztp ?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg of -vr-g,eec2 - (d, dcufrlov /s$O_2$ 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 lift by heating the airyj1 z:ebckdh+h y5 (pp83df a9 inside the balloon, which makes it less dea+9zj efd1cdp:kyh 8 (3by5 hpnse 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 q* n6ngxt ipa q0f839cat 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 92 eiw9 ofhcju8j4y s618.0 $^{\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 ballouw1a0vg4dr .mu;dz 9bon 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 numberypbqcwl*) 3ycw q70 l* of molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many mo.( sea.cf5 e qv*er/ellecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a)l vu0sjsj:35wk 4 mj6m moles,    $ \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 0 w7r3hj+d.aentil2aqqs ; o+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-L breathn(frb.f4py++jy+ x dz; f1hgo you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high+ pfy;bz.4f+1 +yg jfoxhrd(n and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average transl(r sf)b6prhl)f7yst3gl jw1:hrvnzk69 h(i7 ational kinetic energy of an oxygen molecule at STb lnr v97j(rr i:3kht(7)yh1 zfsp6 sg)fwl6 hP?    $ \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 surfa ,es +ylf:71exdo *z 7wzxjjn+/* qtazce of the Sun at a temperature of about 6000 7q,xs* :jzez/+jfwlxe+oa7 *yn1d ztK.    m/s

  By what factor will the rms speed of gas molecules increase if the tem96 d:disvr 9x2(hlojm perature is increasexm69 i2 j:(9hsdodvr ld from 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 fo;o1.wb 4.8yoc4 buvfij1 rtbjllowing speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate thcu48 14o.owrb fjiv j;b by1.te rms speed. $v_{rms}$ =    km/s

  The rms speed of molecubrk)l u:.b9de w-zz)pi)o3eea.-i 5pu8 uirm les 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 gas is doubled:dv2h8 dt,u2j8 p )w5kxhztqq while its volume is held constant, by what factor doekut8q2q: j)w , 5 8txhdh2vpzds $v_{rms}$ change?   

Show that the rms speed of molecules in a gas innzg6 tzcm6 (xw-70b7yk yc 2bs 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 xg6p ch,tw(i 2temperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecular micgwx,pt ( h62asses.

  What is the rms speed of nitrogen moleculesi/- s0vvsxnl99q4ebb 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 spee/ ;h:wv6d qjh aefeher4(w( 5td 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 nitrogenju8o4 i mda+tov)h*fwt,d3 *i molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecul 06kh.tw;uq frar mass is 89 u in a living cell at 376 q0hw. urf;tk $^{\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 written P mt:ex y*8 xla *yczd)/= $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uraniumlcme3zet/grr l.yrw*5,du0as, : mn. , $^{235}$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 pu7wffskztw:s7eh3 4y+1 5ehs ressure, 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 v 7tr3 xpfd,c 6gg3q8pwhen the pressure is 0.01 atm and the temperature is (a) 9x,p3fg3tc v rqgd 8p670 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humla;d.fal v9 kh hh;fe8/)nji0idity is 50% on a day when the temperature fhe a8 dj9k vhnli;/.)0fhl ;ais 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water 6*w -xs jho /ca7o,ewtxab3u;boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular plact zrp61b9r)y ze in the mountains is 0.72 atm, estimate the temzpy r6 )1zt9brperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressit6d ;6+nxdpw1cjq t: ure of water is 530 Pa and the rela6d i+jq6p c;t:tn wdx1tive humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure otu4 9d)tjc/hlyaetdshb ( : :;fu 1md0f water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure j*gg:nocupa7 :31 l/-kctqw r inside a pressure cooker if the water is boiling at a tempekoj/qlc3p rc 1w7t *:a-ng:g urature 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 vozz4u vbbh: 6(,rhgdj-dkx+r9lume 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 of 5 w5+ b 6f-nybzr$^{\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 13m /212d* emthp5zc 7l5rlhq at–4) to diffuse a dist2m5t/ 7zcmd 2q5llat phh e*1rance 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 surihf t1a(d43n23wz ceuface of insects to the interior through tiny tubes called tracheae. An average t1wfti4 ahd2czu (n3e 3rachea 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 h.: elfkpr, .moas 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 measure has beenfnik2*0 w7 nma 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 temperatw6 adsv( 2hic4k*p pg. cbo7k7ure. How much error wscv46g oib .h a77(pkw*pd2ckill be made 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 helium gas cylinder is initially 28 atm. Afte8x-f(f*lv plx)n rc+k ;ndks7r many balloons have been blown up, the gauge pressure has d *vxc8)nllk -+s d(fnpx7kfr; ecreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of aiohvg2;ma xldtw 4n9 z -w+xj8d/a8wy3r molecules in a room of length 6.5 m, width 3.1 m, and height 2.5 m. Assumwl9 +ow/dw m vyz88taanjh;2g34xxd- e the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter h7,d6p.f( wg jqk,k hee8nim+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 uqt8oe k/xv. .dcr r(d8sing the best available vacuum techniques is aboue8rv/odq.x tcd( k8.r t $10^{-12} N/m^2$ 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 utdkoopwce e8: ,p(66*qy:gentce;gp02 xh (L when 10 m below the surface, to what volume would hi:dwn(qc ,:(ke6oyh g;x08p g*eup e2coet 6pt s 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 an8s 5w-o x4lpk speed of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with this spe - wl8n4opx5sked 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 gaibd,yea3z2 ksso s4-g 66hwg*s is 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 oq l0.5if9qsw.nl ;cl zf 770m$^2$ (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 po5*3qc8xv c. cwnu:djressure at the surface of the Earth, estimate the total number of air molecules in the Earth’s cdu:8wjn* .cxqcov35atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules containw 3e*p1roklr; ed 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 has1;-pedl owq/e t15l (ll:gc ff gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder loq1ld-l/f :t l;pee 5(wlg1fc ast 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 liqeyi 4sj12xkb -4s1hu guid 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 gasolin cb9+(u,tzi0 fshmkwjv /c3d9 e 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 snugly around the Earth’s equator at 25hl +p/) t23rz(bg2hd,fdmg am $^{\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 a2ui4xxf+b9cj5 ,f aahue2kz : 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, adopted in the 18mj4 x9q:a 7a6u rwx.lyc9ro 9pex;l0m $^{th}$ 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 chl3rh/fn. d .mharged, 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 z7f vppcl r,1z,b6*e udt8p,othe 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 throwal/l5ijz9m ( wq,5rs qn vertically upmsw aq/5llq95r i z(,jward at it. How many tennis 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-cm-diameter (s oao sf,zl4h:r/s(t6 mpherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is cons:zr6slha o tf/o4m(, stant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the folauoox9ky68:w-ct0/ feyek (q3s r6m d lowing two days: mkx(f o9d38octau:qwk e6ysry0- e6/
(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 Swh ugar*8(.rm,j th .xTP, and when it is a solid deep in,t wu8xh g(a*mh. rjr. the Earth where the temperature is 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 lawxw vbq+2wtr hmoxe:2.41 )zpy to show that, for an ideal gas at constant pressure, the coefficient of volume expansion is equal tot)rx x 2 y4ovmp.+wq2whze 1b: $\beta$ = 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 tot;nm(b06* un rncna )a.u ngf4 prevent rot and mildew. If the cellauf*rna.4)g ntu;ca(0n mnb n6r 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