Which has more atoms: 1 kg of iron wuzsydv cp/- i8pyxq,4:2boz, q:z l 2or 1 kg of aluminum? See the periodic table or Apyxw z:u2vcs,/d2q4,bipl -:q ypz8 zopendix B.

Name several properties of materials that could be exploited to make awzk ylx*5)wtsk:mg(s -:0zlp thermomete xkg)tpszs :w:0z 5wk*ml l(y-r.

Which is larger, 1 C s4w:6 xdvg -g e7.0-hkmejbp e$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in thermal e,0hmg)c7 j58 zbs p ghn9 ij0+shxuy;dquilibrium with system C, what can you say about the temperatures of A, B, and C)7+iuj;8y0h,gbd cjhsp mxzsh905ng ?

A flat bimetallic strip consists of aluminum rir2ymcntg/8 i4veted to a strip of iron. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hin/i rm8gyc tn42t: 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 expan o5/ 3c7 on)j:alp wokp9g6 0qke4eloasion $\alpha$ 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 thermo;7p yn18 u6ay6 esww4ck*sief stat used to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. wwi16 6 ss7acy*4nku8ypee;fThe 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 atyg,0dv,/ kf ob l)y8)snins e9 the ends often have a section in the shape of a n,sn) ,ieb yodsv0/9fy)lkg8 U. Why?

A flat, uniform cylinder of lead floats in mercuryom t eb4(rfyvbfad s+z7s1a5g. lc* 5+ 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 qupul )nk1 n,k.2lld ( 87aylufo*q*b placed in a hot tub of water, the mercury initi au2 lukl1nlb q8.*u*op) yfl(nqk, d7ally descends a bit and then rises. Explain.

A glass container may break if one part of it is heat*7ib md+syff0 u57yp ped or cooled more rapidly than adjs0fy7 md5*b piu7 p+yfacent parts. Explain.

The principal virtue of Pyrex glass is that its coefficient of linear expansiy (.2psjbx h o.trs:g hb0 ,lkmx6wdj-j)c/w*on is much smaller than that for ordinary glass (Table 13–1). Explain why this gives pj k6jl .trbhs.b02*(:w- x/jhdo,y cwg s )mxrise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate as vz.ct) ,hnubbc7m26 bf**dvt 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 33wn79.qp p g.uqxco 3g;t5o;uwxd s scan wil73;oq 3 nsupqoxg;u59s.x dpw t.gw3cl not stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a piston: ido5fcy phb6/-fiw. ), its temperature increases. When a gas /pc6i-oy.fb5h idwf: expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere0y0h2hqbsjbyt jr-, o;u7yz/ submerged in water increase or decrease if the tempzsb;ytuhq ,/by07rhj y-j2o0erature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kineticn:f3lt rs7baaob81 r lr8c) 5i theory and the relation beitr8n:blo5c13f8) ra b 7rlastween average kinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinetic theo( s/8 hhxf6* ua1z:adfjsay;lry.

As you go higher in the Earth’s atmosphere, the / *sx1gs1 f1p-pewdyxk:m8dhratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object muocd0xjx *4dcn:9b m5c+ yy wl/st have to leave the 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 smaocy+0ljd/dy*5b nwx:mxc 49 cller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room tec+sjuz e t;8s*mperature. What can you infer about the molecular properties of one relative to the otject u;+8szs*her?

Explain why a hot humid day is far mor t /kszi,r4q,og6e6*dej o q2ve uncomfortable than a hot dry day at the same temperao6e 62,qjkiz rsqdg o*e,v 4/tture.

Is it possible to boil water at room tempeoepe,+ j ts9g3rature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature k,*jgn 8 k/l6hqun(eme 28rjcis the same but the humidity is different. Which is more dense, the dry air or the humid air at ,jeg86mn8jkc(ken l*/ q2h ru the same T? Explain.

Explain why it is dangerous to open wqb zv;oh67r 2avp0e5the radiator cap of an overheated automobile enginerv ;0qe76h o2az5w pvb.

Why does exhaled air appear as a little o /p(mlr:uf drx6w/6kwhite cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram copper penny?lwsde++u rq .0   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5nrd* )er l zfr:rheh0a yya;4a:r: 6m5-gram gold ring compare to the number in a s arr56hy ;rne0rreadzlya: : f* 4:)mhilver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsius scdttr6 fk)/vu*tv yrd elg:31/ale?t*//6kvtrr3du)g :vldft1ey    $^{\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 recordedts*ud)u9p :kv g5km:j 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 thermometertl(ohnfmfav: )11prx50qr y1t4h mu (, the alcohol column has length 11.82 cm at 0.0 lf m 0: 4r1oxfvtythpmua1h5((qnr )1$^{\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 slwx1 t843gds avabs 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 ag;gzwro3po*mj 7e9z 7pproximately 300 m tall. Estimate how ewom; ozz 7pg*r9g73jmuch 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, rivets that are larger than the rivet hole are ofumr m- sr701d( k/onpeten used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be pl/mopn(d7sue rm1-r 0kaced 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 4 ov3/c:e39 hwua; zz6obbo3rct(5gpfh y,vt 8$^{\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 bewn*: zd8/ pi4(yywiv u its change in volume if it is heated /wy8yuivpn w(*zi:d4 from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 32u wz,;. ,wx l(d+ nluj(dkmdnssf/h7t5 ,aqk50.0 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 ooblad9jr*bqo h9*5-hkrx 9 9uf 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 nlv.dkzd 7 jx,l-)j: zto be placed in a ring made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, narrow vessel so it can expand i, 15r7uz5(jmm adgk:7 4n6uzhald nben essentially one direction only, show that the effective cd,1 n ugk da75m jz(m4el5ba u6z7:nrhoefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the chan 11cpizmrcg4 7ge 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 rectangular plate rhi .whtgm;aurh)35 )of length l and width w has coefficient of linear expr wm;tu)h5 r)g ah3hi.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 isotrov*v3j ):kwcijvz,,kgpic 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 grandfather clock is made of bras+doo;i 7am.oss and keeps perfect time at 1mos d+o7; a.oi7 $^{\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 therh g3rg)yprlpphr7m;7j 0j5 z6 mometer has an inside diameter of 0.140 mm. The bulb has a volume 577grg6z 3pp0)jhm; rpjr l yhof 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 radrg7odfi y-o ta :i1:k;ius 0.41 m is rotating about its axle on ffdt1o - o7; ar:i:ikygrictionless 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 when aomr c8, n:le l:caz.l-t 15°C. How much stress is required t .:a, :c czllm-8oernlo keep it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of c o9c9j 1dxe,dv* s3zvzm1h:pkjaogaa; f ( ;4cross-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 134.12,khp0- u. vg0dizee 7lt cb.yz6 tw0o*2 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 Kelvin scalehzam9u 6q82p 6py byp7 mychk1o2cq)/:
(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 thq/3 pkmi1a tn;t8st1ie Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the 3je(ebscmck1 g-f dwbi: ;)-cEarth 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, airrdlg6(cn q / 6xhdc,s m65w3qy at atmospheric pressure and a temperature of about 20gxd,56cncs 3/d(lyw qqh6rm 6$^{\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 ideaemh* j k4lg6l:ad0 )d25cf peol gas law.    kg/$m^3$

  A storage tank contains 21.eo mpal1 -ucyl3f53er62q- sw6 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 of nih/nv7v+ ,hbd*b7ftudj*v m9r trogen ($N_2$)
(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 4l g-fo19gnyj0daz f+ 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 insidek3 axsi cq,0o2eo1u q/g;gqq; a 35.0-L container holding 105.0 kg of argon gas at 385 K,2goox3s qgqc 1 q/kqiua;e; 0?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg y-4cas q+;eohtbc1 ky:x7 pe: 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 lift by heating the air inside the4 zp*y-fy.f 65y2yaz e)tzzrw balloon, which makes it less dense than the air outside. Suppose the volume of a y-fzay f)z6 y p*yr.5zwt42zeballoon 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 aihrqqyo: (sx. qt)*pl 4r at 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 zd yavd66+/(0dnnnxl 18.0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand at s6 wgpyzsrf f+*jt1 r)1ea 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 mol8cmk:ssmbn51 ils e(,ecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L?h/ o 1-ycy8jc(4tnryy How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) e) sycmod;/v t6w +-cvmoles,    $ \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 . rfn(,fv/v rr5.1$ \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 moleculesj/2b*pkojb-;i.puz f 5gf*9wq ky,u d of air are in each 2.0-L breath you inhale that were also in the lastwpf;jpb k/-*yj,5o.b dq f2kiuuz9g* breath Galileo 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 an oxygen molecule atrq9x1-n(/i cd lw z/bw STP? xi- /n1w9(bc wl/dqzr   $ \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 01y hm4p evdpcjr.t:lu7s)4 ga temperature of about 600m tjsp lvcy. d4re4p0gu:)7h10 K.    m/s

  By what factor will the rms speed of gas molfztj d(qkh9 ,lu1u1nc x6l-k6z y*(igecules increase if the temperature is increased from 06 ju*(k( l , t z6y1lickuhqf1ngd9z-x $^{\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 follv:gin/ g jw6xm9,yt0e owing speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate th ei/v6y:g9x0gt mj nw,e rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in c:,xbbqtn610j crs3e5 y min9a gas at 20.0 $^{\circ} $ C is to be increased by 1.0%. To what temperature must it be raised?    $^{\circ} $ C

  If the pressure of a gas is doubled while its volume-uv+ imd:cot49s.rg h is held constant, by what factor does tu ish-9mg :4d+.orcv $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is gived 7rt9p :qyzy: ngw,+.i4ho +ym wn(qan 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 temperfbo,r l-wg*k60twqs7 ature, the ratio of their rms speed7ob*f0rqkls w 6,g- wts is equal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules contained 6n kurj;0ul v4g5xgldgl9e/d)rns , 3 in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygen molecule at 0ht69*mw 3+zaurvme5sbe8 au * $^{\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 at STPa4zqlivv 2t2a9m/7 +h oap*kc?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is2h5/pe t xo(aa 89 u in a living oehaat(5/xp2 cell 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 gaqf0xh( furks;6 2pr 1j.x0nsd 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 uranium3ykvw(ri c) l,, $^{235}$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 nk)b751xlmsg g( t f+yyb a.u+c p9vi5what 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 is 0.01 atm and thh(xibjdh8 -m0 e temperature is (a) 90 i0(- hjmh8bdx$^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a day whecdp4cy0v 9er 0n the temperature dve cr940cy0p is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place w0m3:wi 3da cmbmot8)ghere water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains iac4mzm.,g6j6l3zd2 n ji1 pvj5nyt8 ds 0.72 atm, estimate the temperature at which water boils. a682zy1 6l5j 3i mc 4m,pgvjnnjdz. td$\approx$ =    $^{\circ} $ C

  What is the temperature on a day whe ls + )0ylkc (;k(b;;nejf uz/g)zvumln the partial pressure of water is 530 Pa and thfln;0 ml(+ ;k(elu gvcyjbz;)/k )suze relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure ofz.k:dl:pa q s5 water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water is bir 0r.yk (s n4fv1:gnyd6e fx0oiling at a tei. rre 0nd:(ynf16yk0xvfs g4mperature 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 volume 680v4h.p99e i f3g dbqg gkg9q8s1$m^3$ 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 os i.qt m1q/e1of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine molecule (sj: muqp83u4r 6jrmw3be 0pscgd(6 8u zee Table 13–4) to diffuse a distance of 15 prj4m38j0 r8u6s6:(bqgm dz3 c upweu $\mu m$ 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 twt2n )f* q/,db5n1y mtliud7rhe surface of insects to the interior through tiny tubes c d* lw d2q)/y,n5rbif nt7tum1alled tracheae. An average 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 b d1ep+pv 9lri i5(fiu4een 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 been calibt(asn5zu,br5 h(v/ewk 7o i d7rated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room temperature. How much ern82w*qe8lv j5o xy gx:ror will be made in a recipe calling for 3008 l5xoy*exg8qw v2:nj 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. After ma j sl5g9x-kxi)ny balloons have been blown up, the gauge prg9xlj-s 5ix k)essure has decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, wrq p7so6qf;m+zh.m *width 3.1 m, and height 2.7fzm sh m* woq;6rp.q+5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the den)pb(q n 93n77 eky1odnfgcos1 sity of matter is about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the bf.c uwek,tdlv/pq7 c;n3z 0 /dest available vacuum techniques is abo kv0n d 7uzl3/fepwt/cc.d,;qut $10^{-12} N/m^2$ 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 mf f2p8b-t8z eto full capacity of 5.5 L when 10 m below the surface, to what volume would 2bmt8 8p-efzf his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon ent0rbeycgr. r.++h 0cl x 7tfl7xers Earth’s atmosphere at a speed 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 t 7c rll egfx00+.bhxc r7y+.ra space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increasedv22n *s2zs sm d6t,nkg 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 0 ((*vyk edgo5nn lt;c770m$^2$ (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 pressureqzw -y)*wr/kyrj+4r q eev4n + at the surface of the Earth, estimate the total number of air molecules in the Eary qvew+je wzr ry*)k+-44rqn/ th’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of n.ui bsfdg2w4. itrogen 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 = 0.+ia lbsocwt:ph/kd2 +4ikj2000 psi (13,800 kPa) and at T = 259K How long will the cylinder lapikst2k:j +hcl+ 0.a 4i/dw obst 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 mercury at 0sreihq fb + /ttjg.w/;,7wx /p$^{\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 at9pue 8nke, qju;w /y a f2ov9ql.4d8pc 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 fv2r m44q/duve it snugly around the Earth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto5 i zs mwc0xyhg/qm6,/ 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, adox4t1h cxi:h;c pted in the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully charged, has a pressure m53k(qi eh8iyof 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 fromj2;rfkkwr ysgx5233loua z - yl-ib+; the 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 graviqhb7ft51c5uqee 8xc0g3l 5 auty by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elasticba8 357e fhqc1e0lqg u5x5 tucally, 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 (spherical) bubble of air from a de*ewq3 my1ej5x 0xx.prpth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a 50px x.ej1 wm*re xqy3perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pr nf/ 1p9*g+dpe),ily3-f) o nrxwa nhaessure in the air on the following two days: )oeh)f 1lwxaifprnnn, ad3 * /+p 9g-y
(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 4ply/b 4hkhg2in the density of iron at STP, and when it is a solid deep in the Earth whelb4y/kgh ph24 re 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 law to show that, for an ideal gas at constant pressur: m:s-zy0 3o9lsbjy:i u cd-hie, the coefficient of volume expansion is e yj:y:is9 :iz-dubh3osl m-0 cqual 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 cellarsd-4 vfjjzdqcb f 3+bjn*0r0/h to prevent rot and mildew. If the cellar izjbc-0vjfj4d f0+ /hdrqbn 3*n 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