Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic table;f g*ixaac+d gf 6.am(8v 1fqe or f *. ef fi+gc m;aqd(a86xva1gAppendix B.

Name several properties of materials that could be exploited to y 0vk96 8 geyyqmslgtydn.l x,),r 0rtg46p+omake a thermomete l4).yeq8ys y t6xpyr,gm, g+ot9lkv60ngd 0rr.

Which is larger, 1 C t ycs -qqivne4:r()4k$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with systek tadwq(ck oe*ju7 08 38qj q,oln;x7tm B, but B is not in thermal equilibrium with system C, what can you say about the temperatures of A, B, and C? a(u3* l7xed0ntq,jctqk8 o; 8qokj 7w

A flat bimetallic strip conssr ox3,3jtjf )q/f.yh8rp /xrists of aluminum riveted to a strip of iron. When heated, the strip will bend. Which metal will be on the outside x s3jrohqtpj,/.8 )/fyfx 3rr 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 lik2adz8h 1:)xexvbv 9xnear 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 us:d (o9xf2dwf hed to control a furnace (or other heating or cooling system). The bimetallic stdfx2fh w:9od( rip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are3h18 *+n1 joo-c/er x-idz a, cuef7alt vve.o fixed at the ends often have a section in the shape of a U. Whyoie 13t,v aco*- a/+dunl8eo.1jvcz h f-r7e x?

A flat, uniform cylinder of lead floatsqghkfd-6+ ( eo va4*ul 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*q lxpvb zp d7n/e,6 oxd955hf hot tub of water, the merc ,95hv exbxn6q o f/pzlpd75d*ury initially descends a bit and then rises. Explain.

A glass container may break if one part of zi; i;mnqs(k,5 dl kp+it is heated or cooled more rapidly than adjacent parts.pk5nm;+(, ; dsqlk zii Explain.

The principal virtue of Pyrex dke 5s5 5 4g9 ,mxx;zggav+ etgdi;:swuxa3 f8glass is that its coefficient of linear expansion is much smaller tg9,vtg8 e: dgwea sa5s45x+5;dxg;mxik3 fz uhan that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate at 20 vre t+ )zw/ctug(ay;4$^{\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 13csp 1b,cg*xn fpb- k9oujk-ak56sito bulge so badly the can will not stand up gak xb391*csi6j--p bpo1uc ns,kf k5. What has happened?

When a gas is rapidly compressed (sa**5ou1wx4fx+v un ciay, by pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of moleculesw4oui 1xv 5 uacf*+*nx when they strike the moving piston.

Will the buoyant force on an aluminum sphere submew,m ) .8r(gvvcqr d,zmo f,-kgrged in water increase or decrease if the temperatu)dr-w,o mc gkvfg.( ,q,rv8mzre is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s lv 097 zb:xcuf 2eesis4aw follows from kinetic theory and the relation between average kinetic energy and the as evbi 0c9xzu2s47e:fbsolute temperature.

Explain in words how Gay-Luss3 jelrwspxw .a++p2+bac’s law follows from kinetic theory.

As you go higher in the Earth’s atmospherer 0 sa9 g-iljocr5e0w7+jg6t p, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refersc s9.-y i ;tai*:6 kr+ eybvvpdy5qhe* to the minimum speed an object must 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 smaller mass. Explain why the Mq:b yi*v * y-a;h+i5cpd ryv9.etk6 esoon has practically no atmosphere.

Alcohol evaporates more quickly than 1xp-k* si)jus:ybd7ur 7a s w,water at room temperature. What can you infer 1rk7uis uxa yb-)ss*,7:dwpj about the molecular properties of one relative to the other?

Explain why a hot humid day is far more uncomfortable t8m:egqq385df9xbx 1s q ud seck wz 1nj;ha.,.han a hot dry day at the 9g e.: z1xaeh knwq mb qc;sfx,5d83su1jqd .8same temperature.

Is it possible to boil water at rf4qr4( +k*r n-,jy 1vjglg ic3mu7aom oom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humidity ilz) :d;6gn gr qoc2;lws different. Which is moreg2;cd) lq gr:;onzlw6 dense, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of a,iq* o4z9jik)c lpdx:und 0, 11ddzn ln overheated automobile e*c9z4iid0 pnj ,dddunqll o ), 1zx1:kngine.

Why does exhaled air appear as a little white cloud in the winter 5sqq8itxz4 go-h+ 1ay d9:6jcz(j pzz(Fig. 13–28)?

  How many atoms are there in a 3.4-i d8ioi zcmnbfd2me-b, 8m7.w /5hiy/gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare te6emm(vg ) zcm:xe/ m,o the number in a silver ring of z( m,e/ g6m) cxevmm:ethe same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken tuhn y)pftsz+;uu: aia. +aa6 1o be 68°F. What is this on the Celsius scale?+) u asuat: fi;z.ah+1pna6 uy   $^{\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 lowgl4j xrkv4 -asp.2 :/5 snzfks5;uyx rest 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-glasswwqsj-cz 0u7 ty)k ki139wdz. thermometer, the alcohol column has length 11.82 cm at 0.0 w.7tw0zswkik zu-cjq1 9y3 d) $^{\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 buapbdf +3 11s nve-9)d:e ebfxgilt 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 by+mgd 31(mb/s /dlmtq uilt of wrought iron approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and January (average temperaturgmy1/sb md d+ql3m(/ te 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 lecl(pf0zz m78o;1 14 x/rlp4//vbz mkgrh lijarger than the rivet hole are often used and the rivet is cooled (usually in dl/j44ib 07rczl/zkmf lxp1 (o;p v8ge1rhmz/ry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter at 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water at 4ou -x8jp q 6z8vlfp6d0 $^{\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 dj9pjw ,6vh 6yt ;jiu*ciameter. What will be its change in volume if it is heated frut*; j,69iw6jj c ypvhom 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is fillz(gfmx0vyy8 m6l 7*s ged to the brim 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 55jn 1wcfvdh9), .50 mL of water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to df(33cc 9qlu zbe 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,- e yqd-+-wjbq2+xoyz narrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximatel+ we2j+qy--dq-b zo xyy equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the den t9/irp,1gb.vj -nozmandqxxq1 (9 b ;sity $\rho$ 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 o. wsmm)-q 6 x1bmwiwu.k dn8ej4me-t-f length l and width w has coefficient of linear expan1xd) njtw8 -m bse.wim-4 6w-.mqkume sion $\alpha$ 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 solibunjr(6mi.); hd r;mfd, $\beta$ = 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.e yi.*eujruoh .r 7;c at 1icy uu.ehr7o *.r;j e.7 $^{\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 anvr58i0j8yrda ixrf6 zj7rq84mpva ( 2wvy/0g inside diameter of 0.140 mm. The bulb has a vj80gi ay a8qjrmvfry0rivwp6 /z24d8x(75r volume of 0.255 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylindrical wheel of radius 0.41 m is rotatinfg 02vu1wa4go g about its axle on frictionless bearings with angular velocity 4o1wfvu ga0g2 $\omega$ = 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 requiredm4ju9yp3o -:)fr* f fb/jkqslg1:wc p to keep it at this length if the temperature increase:ob:-cpflsf*/1 4 pj k3u)y 9gwjmfrqs to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectio 5we 1)gonsie4f tz6k/nal 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 16ro8u v s8l0sgj. 0aq2xm*za p34.122 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 th(fo+ fzy5,wb*) 5mv0z kf klfoe 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 t7-pa7k)oar73d hc m lfx4 fk4bemperature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are about 4000t v;tswkd06a /$^{\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 atmosp,r0 nv nhh+s6x ohra;c: jf03theric pressure and a temperature of about s0no: ;r 3 +fcnh0r6, ajhvxth20$^{\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 5meh1:shk gbd+ 2,bmxSTP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21. xu ,e/9p6em qk.bb/dy6 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 cbklef166 357qigrzbbxyb pv7q w)7n.ontains 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 gas in vyn +h,g0 *yl2hy9pps 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 kz/b+ p k/k+ied.pas j+l2.bpwg of argon gas at 385 .jp sbiz+a+w/k ep2k+b.p /ld K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 km4)w9fal uc6d g 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 the ballooa*kf-uo4tu9cf + vj +kn, which maku - o+kfvj*tku9a f+c4es it less dense 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 at 9d6o n*bao(i- 0ou ddx7: enj ov-jt)s15 $^{\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*e-sdmxse 7 v: pi.,pd.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 balloaoh;kjl--6hl1 eef0fd ax 5z*on escapes a child’s hand at sea level and 20.0 $^{\circ} $ C. When it reaches an altitude of 3000 m, where the temperature is 5.0 $^{\circ} $ C and the pressure is only 0.70 atm, how will its volume compare to that at sea level?    times the original volume

  Calculate the number of moleculehvgno .fyy8xk748 6*ld )d rces / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many molecuzpz- uz0dcam54m 7ii /ht8uh1ecv7vcf+ v,a9les?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) oessz dox-+r *l3k.t/ 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-py7 lc1+pb qdzm qg;1 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 eachwu8dq / smr7+m 2.0-L breath you inhale that were alsr7dw /m8+mqsu o in the last 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 kskg ,t8u f9m8cinetic energy of an oxygen molecule at STP?fk8s, gcm tu89    $ \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 atou*5m0bmg rs o/ms near the surface of the Sun at a temperature of about 60*0s gombru/5m00 K.    m/s

  By what factor will the rms speezn1(;wzk h5a 7pzpvh (d of gas molecules increase if the temperature is increasepa5hkwh(p1vz 7zn z(; d 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 following speeds, given in units of km/s: 6, 2, 4, eqp 4 km0lk q7e2(;jzs6, 0, 4, 1, 8, 5, 3, 7,0pj mlqee4q72z(kk;s and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules 1ctrkj6d ohs8ge 11a) 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 do5venhzb9 v80 c8 5qvmzubled while its volume is held constant, by what factor does v bnz5h9 5q0zcm8ve8v$v_{rms}$ change?   

Show that the rms speed of molecules in a ga0a6( zw-m i 0w*ou5-ykqgodlg s is given by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixtu/;xjg hwy8b h2a 2gn-ta-vx2 zre of two gases at the same temperature, the ratio of their rms speeds is equvx -8nt-aw/2ygb;g h22jazxhal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules contained in 4g- 1c iums)nian 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 atis+p tuso44di/j. s 3x)q3tig 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 distc29y3rghd,)r6w uls q ance between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acidl ey;cc3n.xb. whose molecular mass is 89 u in a living cell at 37.;eyb3n.l cxc $^{\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 a7wafw*4l ezj * gas 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 u8wzop(* t8+f3puqn w zranium, $^{235}$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 pressu7x o36v:stz. 7jyo ta1:hpjbjre, 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 whenfkr2o v (n lkbx/8;c(x the pressure is 0.01 atm and the temperature is (a) x(;kx2 n (8flrkovbc/90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a day when theby5jgx:r6,c m xti36e temperature ibcg x j,ym:65erx it63s 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where wa;wmp fwv+)x/,;rvhjeko (*x hter boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particul thj* i1+iicw2ar place in the mountains is 0.72 atm, estimate the temi w2h*ti1 cij+perature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial tvuq)*b./ 2na7 1tb.vh8 /h yusbsjis pressure of water is 530 Pa and the relative humidity iss1. 2iq hy/jub *ba/nt7 s) t.vsubvh8 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of watebiasz/ e iu6f2n /g)ea.0kx x6r on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside jl5 z-(d45*jyhjr k3qoyytk uw. u+b3a pressure cooker if the water is boilin 5zk.jo u-+(yjyhbjt3l y3wk4d5*q urg at a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a ro:n9pbpae2m, k;nhxil h14 op,om of volume 680$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dew point oirs,5q xg(ym)t 4l5z kf 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 a0umdfb( u;b 38rzjat2 glycine molecule (see Table 13–4) to diffuse a distance of 15 rbd;m38 fajt(b0u z2 u$\mu m$ in water at 20$^{\circ} $ C if its concentration varies over that distance from 1 mol/$m^3$ to 0.4 mol/$m^3$ Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u. t $\approx$    s ([color=rgba(0, 0, 0, 0.85)]Round to one decimal places) $v_{diffuse}$    $ \times10^{ -5}$ m/s
$v_{rms}$    m/s

  Oxygen diffuses from the surface of insects to the interior through tiny tube-d6 znzyrbh .6r /t,u8yzfi6z s c zz.y6n/firz 6zyubt ,h6d 8r-alled 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-/m6bmi/ kt5 v t2jg:tdfs4pieen 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 calibrated at 20w-kv f10slp gj7za-h 0$^{\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 tempexp m7fc4+zpzwih,rl k ; 0 0j61/tpnvx19 izkcrature. How much error will be made in a recipe calling for 300 mL of cool water, if the water and the cup are hot, a 4 x;c/+z1 cj wz ipnl91pfmrxpv,t0k067ik zht 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure i+; w3 x +5ilaokacudc/zg6k1un a helium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the oz /kwicxa d ;+kgul+31au c65cylinder?   

  Estimate the number of air molecules i-tt cy.d3. xv 9 kfyi*8ppkd9vn a room of length 6.5 m, width 3.1 m, and height 2.5 m. Assum*v9 k8f-y.tty 9d pp3xik dv.ce 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 onmsh(63km8bo9yhv 3 ug+ala d-e atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best available vacuum te;lqj (dosu;ifib6 ,6 bchniques is about obli;(udjf6i,;q6 bs $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fills his lungs to full capacity of 5.5 L when 10 m be -:fuabdqd9 m : i1ajh12c3xcdlow the surface, to whatj:i2ud fam:1 -bcah1d3c 9dqx 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 spe 2- patovc-yt/jwdkx5-* z- xied of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the - j/oaci -v*--xxp2tw5kzydt vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of anq6bm3p ar 1e*f ideal gas 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 ofjpxt3be e0o 3ftz- zezfgpe)l1s8n0 5ln,5l* 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 atmocvuo e;2xi-(p b8ix nst,k+8b spheric pressure at the surface of the Earth, estimate tx+8vnci2; kspoutbi8(xe,-b he total number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen mo9j9gqwy84hfm ; sz 3oplecules 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 hc,yo,0s5bw st3hdz3gyb; (hjospital has gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, mb 0stzyhjhcg 3 ,sw3b;yo(5d,easured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a b4 rvrrrv8nj45owl of liquid mercury at 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasoline at ggeb 89kp 94bmxzhf* 30$^{\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 c i 4zs/q0b/s+*uun wsat 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto;4o9s jt+p /v y/vwzqt 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, adopted b-q 8s xxm) xz+nrj8x d;er:g9in 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 of 195 atql sag7s+(-wmea ,o7j-3wly3 zmcw u/m 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 E(sb.oih qke/ kq0jd 4(arth 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 throwsrlmvb;a39 r1g v2s (l(h2cdin vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and m2bs r3agl1l(9; hv(2s dirvcare thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm- ig w33k.t,dwl1td0dg 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 thg l,0.3ikt3dwddgt w1e bubble when it reaches the surface?    cm

  Calculate the total water va+ksn-xd td,k 6c2bq6ipor pressure in the air on the following two days: xnbi- 6d, kc6d2qkts+
(a) a hot summer day, with the temperature 30$^{\circ} $C and the relative humidity at 40%;    Pa
(b) a cold winter day, with the temperature 5$^{\circ} $C and the relative humidity at 80%.    Pa

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

  Estimate the percent difference in the density of iron at STP,ykc)5l+;aq ywjp3 r i0y)znf3 and when it is a solid deep in the Earp0a5n 3 jywq)lk; y+fy3ci )rzth 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 law to show that, for an ideal gas at constant pressure, b va.cb2 rvn0mk,q6 33dxye:athe coefficient of volu r2mbdb c v:.y0xv3a,a6nkq3e me expansion is equal to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.