Which has more atoms: 1 kg of iron or 1 kg of aluminum? pyj3ap);j-26n egq n6bgof5z See the periodic table or Appendix B ynn 3zfpj-; o g2)6bqja6ge5p.

Name several properties of mz ay8h+da qd:d63dsl (aterials that could be exploited to make a thermometdds3 z(d:a dl8 yaqh6+er.

Which is larger, 1 C hb5 r,xb(ki,t $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with systawz:b c7-k (btem B, but B is not in thermal equilibrium with system C, what can you say about the temperatures of A, B, and t-b: (a7kzcwb C?

A flat bimetallic strip consists of aluminum rivetii):d o/f;yq led to a strip of iron. When heated, the strip will bend. Which metal will be on the outsidelq;fod i:i )y/ 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 v- x/5+hcqa gzt+kg,p of 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 a simple thermostat used to control a furnace (oz 9q tx4:kbqrw ;xh,9or other heating or cooling system). The bimetallic strip 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 cont,boh4 9txkq9 qz;:rwxrols the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at the ends often havev ipov)uzcq6p*. t6- fd3qw0w a section in the shape of a U. Wf0 u66tq3-op) wzq.pwdvvic* hy?

A flat, uniform cylinder of lead floatnp6+ctf.7) l8sl hnrqn4*8nrr u2 f lj*beq+ss in mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-ink y7i1hr /g0ov-glass thermometer is first placed in a hot tub of water, the mercury initioi/gy k r071hvally descends a bit and then rises. Explain.

A glass container may break if one part of it is heated or cooled more k4y+) yxjcuzg+ nf 5w9rapidly than adjacent parts. Expla cx4)yyf9n+kuj+g 5z win.

The principal virtue of Pyrex glass is that its coefficient of linear expansion 8dinjudd (rhj exrl.f4 2w*:3is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex. rdn le*d8u.(ijhx r3f4d jw:2

Will a grandfather clock, accurate 8tflrp)7,mb be 8ux9op)g,g iat 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 it3t2 zbm y4-vcas bottom and top to bulge so badly the can wilya3 t2cbzv-4m l not stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a piston),nckag7qf. 4dp w: ,wn).ni ga, its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kiwacggkf 7a :qn.iwn .4,dn )p,netic 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 water increase ob:pl ivwoe* 37r decrease if the temperature is o*7w3iep bvl:increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows f4mee2 abs+p. irom kinetic theory and the relation between average kinetic energy and the2 apsb eem4+.i absolute temperature.

Explain in words how Gay-Lussac’s law follows from kfsbkq p561a+f evku,g yh12ll/ i)l d(inetic theory.

As you go higher in the Earth’s atmosphere, the ratid+kl(x9 l l7eko of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers .px6 / k;a wf6ighscl:to the minimum speed an object must have to leave the Earth and never return. The escape velocity fc .:; 6k wsi/pagx6hlfor the Moon is about one-fifth what it is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What can y tkgy /dz4+1jeou infer about the molecular propertijg te4z+kyd /1es of one relative to the other?

Explain why a hot humid day is fdd19v(1v rq hgar more uncomfortable than a hot dry day at the sargd9vdqh (1 1vme temperature.

Is it possible to bo9j :*;f-y 3 nj. g.qspokldtvgil water at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when th:b:uhtw jbwj4jv8gu*ot-q53 e air temperature is the same but the humidity is different. Which is more dense, the dry air or the humid air at the same T? Explaj 34b *5uj :jwh8vtbwou: qg-tin.

Explain why it is dangerous to open the radiator cap of an overheated au k:;: q(hn8v 8fxokq1v5nkbgitomobile enginek bi 8 x(n:f5v8gq1v:k ok;nqh.

Why does exhaled air appear as a little white cloud i5ytnwl -7cgpo bm0s m)v.o02sn the winter (Fig. 13–28)?

  How many atoms are there in a 3+-wm ix ug3.m:lz ,jguylk*(e.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to q2j7 h5phhh:x the number in a s5jxhp q27h h:hilver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this-vt/cow j hp2: on the Celsius scale?w-h2j: p/tcov   $^{\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 p dx(44i a*ewhwl,zn (q:9id etemperatures 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, s*:; bqjnbyh3the alcohol column has length 11.82 cm at 0.0 h*s y;bb :n3qj$^{\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 lonjlzg roy +ou5a1(go* 4g (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 appim; 5;w art aknui9 obl5k/3u0roximately 300 m tall. Estimate how much its hu;; ai0 lonwu55m9tk3bk/a rieight 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 riveq(xxcn07par.b q pkd w ltge ++a8,:d0t hole are often used and the rivet is cooled (usua+gc+ k( wd0ppb adxa,q8 .qle: n7xt0rlly in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter at 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water atzwd ak6h qsf;3ecr;z.r;(nz 3 4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. Wh c b54k 3mkkeypiwu6 do::l3m8at will be its change in volume if it is heateddy u4em:ko6pki5kc 3:bw3m l8 from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.8+2+yjg f podo0 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 of water atv01 kw *afc pa6kxh-1k 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 to6p 5wt(bm9 3skcm/z nj 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 zo ,1j.d of)mrit can expand in essentially one direction only, show that the effective coem)r, j .o1ozdffficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change insk6- c:m le3ei 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 platee dl vu-ctyke9qo*+j(6q6;yed qg * *z of length l and width w has coefficient of linear expu ke-;vzqo6t ycy e96*(qd+gqel**djansion $\alpha$ 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 isopu+7hi. fh vh2gj4-hai fo42otropic 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 iz8lw+ tv5nk(b buc9vq)m pb7 k4 6p0jvgptw/ (s made of brass and keeps perfect time at 17l gzp()qu8(5b/0tp +mv 7nv wb9kwcvb4jkp 6t $^{\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 inside diameter .v)nz2z vcxo,v akq/ dj:5o,bof 0.140 mm. The bulb has a cjvza2),zbx:n. dv5okv o/,qvolume 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 rov;d t/) 3hvaswtating about itsw; )hv /tad3vs axle on frictionless 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 lengti nqxx-bp8mp j1yt +l e2e,d6;h when at 15°C. How much stress is required to kebnip+l ,;6ty8 xpq ee1j-mdx2ep it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectiu*4yrfa0+x7 -y ag*mwdlxma1 onal area 0.041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 134.122 cm at 20 3zo +de*ojrb .*+eigm$^{\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 o(6 n(/ov0et* j.(va e xqcv4deofud 8hn the Kelvin scale:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temperature on the Fg 9s69s di. 8xdyb9zba2pof*u,sn 74e 4qlgp lahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the s;, u toc ;bnb6qlaa:,Earth and Sun are about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

  If 3 $m^2$ of a gas initially at STP is placed under a pressure of 3.20 atm, the temperature of the gas rises to 38.0$^{\circ} $ C. What is the volume?    $m^3$

  In an internal combustion engine, air at atm1:b6hpf vez4f ospheric pressure and a temperature 6 hz:effb pv41of about 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at STP using ths05evdtw1 2( *w+0ivxaqm 2vqzccbt6e ideal gas law.    kg/$m^3$

  A storage tank contains 2 o)i ,gsvjac50. bn8(tir tqz*1.6 kg of nitrogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.5 kg of nitrogen (are0mf- h,i+u$N_2$)
(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( a5/vox8c2eq lg6ow n 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 abhjy :etoj+3xh.rtm/2 l;5h o 35.0-L container holding 105.0 kg of argon gas at 3ytr 5xl.e h3: hh jt;b/o+j2om85 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg ofmu/3 sug3gx)m $O_2$ 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 hv ee,c*s rhgs 51p56ereating the air inside the balloon, which makes it less dense than the air outside. Supposes p*s1her6 evc,55egr 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 aqgv aui(t ao,e:u*.i4ew u/0fir 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 v;d v+tmxog3,/q pe1h at 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 rtcx+i7clvj ;8;5xd f4b boo0a 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 molecules9og6(zrn/5k (secxq b / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 ri//dq-qy)zs L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) m*rbj1w bg/ 9wroles,    $ \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 5.*e -lku :oz,wt9c+ncy1$ \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 breath you inlg xq irstssboc,5+ w:etzg7 +49ir1+hale that were also in thei 5+c4so+qx7+:igbz t9ltg swrr 1se, last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the averp+f;f )r)fp8 p /7ihiaori;tj age translational kinetic energy of an oxygen molecule at STP? a; tr)ppfh)8 ;fif r+ip7/jio    $ \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 ooaubb bb7fj;,-2 ev7kvu.o1g f the Sun at a temperature of about ou7, .kub 1vob;7gbfv2e-a bj6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if the tempercq w o5.l7-:fb ;c 0r1s,:+waofgk gwr nqjvm)ature is increasvqkb:5r rw aq0gj f7.- w ;msclf)o,cnwo1:g+ed 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, gg8-d:gm-6b z davy1 gqiven in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, andm: gzq-d1vgg6 y8da-b 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules-b.ljeom, j ,j 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 while its v uqvj: j:f:sv)olume is held constant, by what facs)j quj:: v:vftor does $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given det ,(bc. x1c zfer8eg0h*ym9by $v_{rms}$ = $\sqrt{3P\\rho}$ 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 temperature, the ratio of :znwi 9 79kkh5xna8m3di o7by their rms speeds is equal to the ikwi9bnm8h ndika7 z5y: o793xnverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen moleculeo4)p,jw zyvlt 2u dja le/m4..s 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 speed of an oxygedy m/oc4sc 9u.n molecule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance between nitrogen molecules at Soaf7ekzm* mpj-og2 6) TP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u lszzw(u p pt(:qf5h,1v 8n1ri in a livingv5nlfr(tu1 zswhz ,8:pi1q p( 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 gas can be wu+ 4s fpyqab+8ritten 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 hnpjxjf,y h9(rme c: q m)(7vle7.fr9uranium, $^{235}$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 pressp*j 8fvwe ,2bture, in what phases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressurerobk5)ag1k2b9l v c bl 52rj,w is 0.01 atm and the temperature is (a)gl 5r) vr9,a51cjkbowb l22bk 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a day w3 pwi psr9haz-10;zzsix b7 t)hen the temperatz9 s a;3bi)xrswz 0-7iphzp1ture is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place whn;-zo-q4 5 5wnwprhlpeahq6 )ere water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular f --+n/j 6ulgywo x(-,wefgmo place in the mountains is 0.72 atm, estimate the t/6yo+ggwxw-lnmfo,- -(ej f uemperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water5uj pq1k- sjh4a9)a *nktpq9rg1i n, j is 530 Pa and the relative humidity s-k4t 1 pa9r9uni 1nqpq, j*j)hkj5g ais 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the temperature is 25 /im3e- m b8c3jhx-ct37kirqc $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure in1,w7 8eh0cpikdr9inwside a pressure cooker if the water is boiling at a temperature of ipw ,0ce8d7r1k9ihwn120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of vol ichfbj/5 :umd8q fc99ume 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 poig z(x(y;) jal*t0ershnt of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine moz )xsu.b9cx1xuw* kd:q:h8nk sa4 wu1lecule (see Table 13–4) to diffuse a di8 kbw )xs uuxk.49xucd: z1*whn:qsa1stance of 15 $\mu m$ in water at 20$^{\circ} $ C if its concentration varies over that distance from 1 mol/$m^3$ to 0.4 mol/$m^3$ Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u. t $\approx$    s ([color=rgba(0, 0, 0, 0.85)]Round to one decimal places) $v_{diffuse}$    $ \times10^{ -5}$ m/s
$v_{rms}$    m/s

  Oxygen diffuses from the surface of insects to9gt2s3i ,xj4ccl*4 e scu)y tr the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has crc9cste3)gu* 4 j,rxcist4l y2oss-sectional area of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been capigr ;4khk1tm oq o*h3- uye.*librated 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 hasnq wt8htbgr.w-o1 y07 been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room ) eunm376ybxyj33d 2 dnump-btemperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water and the cup are hot, ae3 ) m3uupmjd3y6b2n n-7byxdt 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a helxlg1-i,-mmn ;de+/ipx sky: nium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction ydp nk:lxni1imm,/--+x gs ;eof the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, wido+ /5h)c/b+dxjnjch6lf q b7m th 3.1 m, and height 2.5 m. Assume the temperature/n+b) l5mfc qhoc 6+jdjhb7/x is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter isj w9gp o2ym:5; j ),(bbmmhsia 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 attamh inh;:*k*yminable using the best available vacuum techniques is about* mmk*:h;ihyn $10^{-12} N/m^2$ 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 sq /ed(5w mfhc 5qp(irz 50u5abelow the surface, to what volume would his lungs expand if he quickly rose to the surface? Is this advisableaz5s5w h re/m5(q(qfpdcui05 ?    L

  A space vehicle returning from the d o.-qly)c lnyr .5f5v88unwbxp; y9yMoon enters 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 noun ynwp.-8c 5lyxd8qv9lo.y f;b )ry5se 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 gas is inciade fhoxw/a :05+aob:v6z* i,ekm/hreased 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 7b j1k.7 fk zu)bbn(gb970m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at the surface ofyh ;og-dzr4:ft in4x +f5ku3 t the Earth, estimate the total number of air moleczrf434 fxt-kyudn ;i g 5:+thoules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecu. sl.d43qr bnqles 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 =pc;:d rac/ay6m t::l p 2000 psi (13,800 kPcdp a6;t:a/y mrp:cl:a) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid mercu b3y.;b10e lzak bw:syry 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 qhidm9u6j3o5 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 ary k/aou4c+yqp ,njm7.x u t) pc:mt(o5ound 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 onto a glass fx3y lxzb/j*bz68d.yheg ,j9jar 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 stah;yg(hr j;uts3xp* (w kas0 g2ndard, adopted 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 o9)6g *htmyozhbn d4* kf 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from the Ear9acs2vgj2d ;hyu(j .v7a y;ipth 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 gravi vh++hvn7 b jh-x/d,ylty by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at h-,n+jdx/hyb vl7 v+h12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubble of air from a depthlbf 8lbvi:1d ( of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when b1b:ildvl( 8fit reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the following c;iu g5b-kc/qtwo days: / ;b -5kigccuq
(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,3lb -7z 1d joiaqb,v2z and when it is a solid deep in the Earth where the temperature i,o qv71 lbzb2d3azj- 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 constano 5 zo*ix6rc3bj4q:lmt pressure, t 4bioq*m5lz 6:x r3cojhe coefficient of volume 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.

  In humid climates, people constantly dehumidify their cellars to prevent rot and6 (wnzk 5bi2sg mildew. If the cellar in a house (i 62k gbsnzw(5kept 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