Which has more atoms: 13gbv:qu)76pva7 x g-c8llp h s/b-wk e kg of iron or 1 kg of aluminum? See the periodic table or Augpxh:7q)/8 3gp a7 c k-6b-wl bvvlseppendix B.

Name several properties of materials that could be exploited to make a thermqqle ;jn*n8kp n 5yy) hu924ls/jou(i omet ;jq 58j esu h4ynlnpu29 i*(o/)qknlyer.

Which is larger, 1 C 3qnc zt2) rx-(bzl0 ox$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium 8ef6 aejb0: zrwith system B, but B is not in thermal equilibrium with system C, what can you say ab 8fraje:0 eb6zout the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of irog,cu0fuq u :5xn. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hint: Seex f ugu,q50:cu 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 h )6lutt2q3l1su+wijsion $\alpha$ 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 couvc(xb p-a0n1 fh-5fi ntrol a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel contai --fv1i5(ax fcb nuh0pning liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at the ends oftqu9ta4+yl ogh+ *pi4hen have a section in the shape of a 9 yo htha4+4gqi*+lpuU. Why?

A flat, uniform cylinder of lead fl)3nze 4i*dq dboats 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 yftlmed 0-p5xh x hpdv.:0)it ct:;c9/ hb5dofirst placed in a hot tub of water, the mercury initially descends a bit and then risesv:.b:d ;p0l)cxo9m p f0hy thd-55 itc/exhtd. Explain.

A glass container may break if one part of it is 6rzmio sbfxn-y;;s(8 kh1o5f0 kt0z pheated or cooled more rapidly than adjacent 6 0kn tzb fhi fo;1k8x5(om;-yzrss0p parts. Explain.

The principal virtue of Pyrex glass is that its coefficient of linear expansion-hu;y kdi +vg. is much smaller than that for ordinary glass (Table 13–1). Explain why this gives kv. gh;diy -+urise to the increased heat resistance of Pyrex.

Will a grandfather clock, accv adkuw+8z,z4o3x-u kurate at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and top to bulge t9-.yxo da vio 5r h41vzi33 fuv:yg/nso badly the can wil 5g/3voxovnu.fdh4z iy1yit :-39avrl not stand up. What has happened?

When a gas is rapidly compressed (say, by push-vae78 oj :qg, (vfthjki3eo1ing 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 otj(ego1,8ojf7-va :3ik h evqf molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged in water increaspu esos /ook6+7rbg9w ;ax5 ;xe or decrease if tge;k spw+rxo ;o7/6o 9sbau 5xhe temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic the8 sbws,df.p6gl:;- lja bie7o6nkk*d ory and the relation betwee k j-8ni e sd7f;6g*w,6:ldsa.obk blpn average kinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinetic theor 5ud)y bmld9fi2;h s-uy.

As you go higher in the Earth’s atmosphere, the rh rp*v37hz 6xtatio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object mus krt 4rtm.d76gvmb+ j:t have to leave the Earth and never re: dm+k7 .4g tvjrr6tbmturn. The escape velocity for the Moon is about one-fifth what it is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water q0(d,- kdrj,ygrd9 rdat room temperature. What can you infer about the molecular properties d( qdr0dkj rg9d,y,-rof one relative to the other?

Explain why a hot humid day is fat7wy rd8f 9w6e ywt7z1r more uncomfortable than a hot dry day at the same temperatwt71y9 8 wryd6 7ztwfeure.

Is it possible to boil/y53 f qsi*ned*pio6 k water at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperatur(z(d 1,qkcz ut/mc2fue is the same but the humidity is different. Which is more dense, the dry air or the humidmku(,1tf/ (q2duzc zc air at the same T? Explain.

Explain why it is daf* *pfl ko,ob9ngerous to open the radiator cap of an overheated automobile engine.lp9bf* fo*, ok

Why does exhaled air appear as a littlerzdet(v70wv4x4 ns +w white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram covuz6 t7fut:.u pper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to tv+ c3i6hmbzd p.t oqy-ux*+u 12 sfid8he number in a silver ring of the sc.t udyx1o+iv zb*mdpf-i3+2 h s6uq8ame mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often0e fj2bs( 2bnn taken to be 68°F. What is this on the Celsius scale?nn022(f sb jbe   $^{\circ} $ C
(b) The temperature of the filament in a lightbulb is about 1800 $^{\circ} $ C. What is this on the Fahrenheit scale?    $^{\circ} $ F

  Among the highest and lowest temperatures recorded aa*1um68yu /q-i xoi fpre 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

  (a) 15 $^{\circ} $ below zero on the Celsius scale is what Fahrenheit temperature?    $^{\circ} $ F
(b) 15 $^{\circ} $ below zero on the Fahrenheit scale is what Celsius temperature?   $^{\circ} $ C

  In an alcohol-in-glass thermometer, the alcohol column has lengta. 0,-xpdynqth 11.82 cm at 0.0 qty pxa,dn-.0 $^{\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 eqi/ .qo hkfb1iq) i1qfz c)2;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 apwobhj 62.8 cu7 t(:mlwvb. dslproximately 300 m tall. Estimate how much its he2lu6m wjc:o7v bdthbls8(.w. ight 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 arez+dvw -a8oetcrt )r6 5 often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm -cowrr zat8+t6e v5 )din 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 (uai(,4 t ehxgq(bbfh1k +j,c4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be its change in v9dy1g ;l:s zjdolume if it is hgd jly z:9d;1seated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL of wwmqiq 606srw p d:*+rtater 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 55.5pvzq.b1ehtob7 lb+d42bm+4 y 0; ptq xr17qxd0 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 be placed in a ring madec1 efb (:r7hkztdh3bx r;bi2+ 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 e(jn.eq/l+5u.rbn m y zuc18abxpand in essentially one direction only, show that the effective coefficient of linear expansionc z8/nr1nam5.b be.y+ l (quuj is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the chqo8 -jur5b*ud ange 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 of length l and width w has coefficient of linearb-6;:f vjjka w expans;wf-vb6k:jj a ion $\alpha$ Show that, if we neglect very small quantities, the change in area of the plate due to a temperature change $\Delta$T is $\Delta$A = 2$\alpha l w$$\Delta$T See Fig. 13–30.

Show that for an isotropic solxe 8eznboz g(w,sdjj9*-m(0mid, $\beta$ = 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 at 1 iy(gqnt2p 1:uy ucp91(uy9upq11i pgc 2 :tny7 $^{\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 habg: fg *l /iamp9vn/pq78o/c as an inside diameter of 0.140 mm. The bulb has a vavc*/l9o/g8 pp:bfmaq i7n g/olume 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 rotatlna:q(ev8uvr )s-;cvb w- qv*ing about its q8qlv sbuvv*r(:-v -;)wcn aeaxle 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 length when at j- 9u a1h/fyzw15°C. How much stress is required to keep it at this le1yza /jwu -f9hngth if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional area 0.hm-(a ke, )kt hc.pmmv. a7.kn041$m^2$ 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 1j3t4iwyl rs ;q mpfo.a4-1+zx34.122 cm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on the Kelvin scale: :j zz2 gwya.1v
(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 te s1sn7: in7e.c3sms ve40ke pbmperature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are e 1oen x qbo7y/rn,4y(o orw2,about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

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

  In an internal combustion engine, air at atmospheric pressure 1yc2 +n2tucul0m m2bfr3uq -q and a temperature of about 2bu 1+22t0q 2 cf uqryn3mm-clu0$^{\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 densityp5a+ nx ;dh 6dx9xkdi- of oxygen at STP using the ideal gas law.    kg/$m^3$

  A storage tank contain))i.bn( vmig r.)zbbhy l9m)vs 21.6 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 o,fejt.ivdnc pveygq*2/k y+ )p 0 kh,/f nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gasgv a)li;o ulr 3i54uwz87ar(k is at 10.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure insp3 nhp3 j*qv2oide a 35.0-L container holding 105.0 kg of argon gas at 385qjv*no 3p3ph 2 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg of ik0b05owh0j 4 7uil il$O_2$ 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 buoyft 8d/nprm 7me29 ,twfant lift by heating the air inside the balloon, which makes it less dense than the air outside. Suppose the volume of a baldef m9,2pm87wfn tr/tloon 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 witp wc l0zj9p/v6h air 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 qrzb ufzw ,z ))h234lhat 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 ch nx tle98wt u-ms4j+zwsdp6r.-3b +cuild’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 molecuw 3 hzmf(q :l:nlm2rf+les / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.00 ahfpj.:71s;;bk dhaz0 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number og9u+:cezu, ane n6js f)c 7z7rf (a) 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 volum3is,zhg: dl hj(0k a:le 5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L breath you inhale that weh-( n7 21(pa kvhfkwdlre also ilfwdka k( h(2h7v-n 1pn 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 translationa uu9* s:p)k p;jj-omwrl kinetic energy of an oxygen molecule at STP? k;mj* up :rps 9o-wu)j   $ \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 yj52rpb/tg8)g , fpz+jbe 3 henear the surface of the Sun at a temperature of a3e e g2,r)g 5fyjb /jz8bhptp+bout 6000 K.    m/s

  By what factor will thepik.le, tv *p1 rms speed of gas molecules increase if the temperature is increas,vip *tl.k 1eped 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, giv-5c c h ;cq(vag+rvdw+ab+v )j-xw0c een in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Ca hac- q++ 5eb0a;v)wvwj (r+vcc-cxgdlculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a g-z1pbq)7e se luaxf /;as 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 is hepqz-u/gi)a+qei y ,n)ld constant, by what factor does -gqqe)) apiyz+n,/iu $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given by pn;s r-1zgl nv)svq0 ;$v_{rms}$ = $\sqrt{3P\\rho}$ 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 temperaturew2; 8xabds18ilr s h2g, the ratio of their rms speeds is equal to the b 8;1i2lss g8rw2xadhinverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules conu q:p1etj qnj5zd28p )tained 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 vl++ebt//iy j97 jtrdan oxygen molecule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance bn l3 m80;/rcb 2flaukbetween nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose mohhczn4x +o -k o;8yrs.lecular mass is 89 u in a living cell at 37y oz+.x;kn4o- hsrc8h $^{\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 gfm sc(.6tcp6p as 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 uranium, 2dee: j1/lfk2.xweoy $^{235}$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 press lvqtjcg:* rfb/ ,0pp6ure, in what phases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure isf;b)ieo1e)r h 0.01 atm and the temperature is (a) 9 ) ebei1ofh;r)0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximat;ew w8/ (mk)z tz37mpn mey6fwely) if the humidity is 50% on a day when the temperature is;zfkwmw /7e m n)mz6(w83ytp e 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boils ahz9tqwuck/d4/2fb9 ;8j xff/g tjb(bt 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountainitw4x60b 5l4q, jvkng s is 0.72 atm, estimate the t 0lq56w4 bn,gijtxv4kemperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressvc 9l 4a rne.4jp1b6weure of water is 530 Pa and the relative humidity91.ec4j wla nr64bevp is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of wateuh/4ah+vgrp8z .sxbd 2u3 xu id (af(/r 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 i2 yxbrb6b qgawb0:j+.f the water is boiling at a temperature ofxw+. 0 26bgybajb rb:q 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a ro 1jrqd2gt jku0y4h *9vom 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 of.h9)s :s5wu yh7t sif7 o-mdm5aesi :b 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 (see Table 13–4) to diffusjirf8p yp s02/ed:h:rw v(at2e a distan yejpdrv82: fs2r:0(tpa /hiwce 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 to the inv 1cc2ll ir-mqhpc(* ne1frq7:z6s* 5 .lhluyterior through tiny tubes called tracheae. An average trachea is about 2 mm long *r7lvlhf(l:p2i1 ue1sl nh6- c c5zmy *qrcq.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 been3s o57lvgvrda n 8 7j(s6sjva) 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 nkk z;e0 4)v dyxt,aq4,zsg/c has 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 roomwr*(ja bpis:2j) g-y qqjn*m( temperature. How much error will be mn(j*a -iw*yg: (bq ms2j)j prqade in a recipe calling for 300 mL of cool water, if the water and the cup are hot, at 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a helium gas cylinder is initially 28 atm. After many baiu.5xlqm tb: :lloons have been blown up, the gauge pressure has decreased to 5 atm. What fractionuxm5l ti :b:q. of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of lengthzr yw )l*z)rt(fk w5,jgr6fo* 6.5 m, width 3.1 m, and height 2.5 m. Assume the temper*r*r(lg 5zz t,o)w6) jf ywrkfature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about h5jeyf* 3zfi1 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 best available vacuum techniques is a+z4w u6( ro 3kavguz7aboutg6kuz 4 z(awuavo r7+3 $10^{-12} N/m^2$ 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 4z)af8qj* o(plh vut3 1o3 ;agtu+wjrto full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs e+4a3q) hwauo(tf l3u 1gpjrot*;j 8zvxpand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Mo wi e.4ulqdv*w)78mpi on 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 corpm q)e i4 iu7wd*w8lv.respond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increased fsz0mdy:6fzgx o*;lio1i 9ew+ rom 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 volumeraz kd8kp7 n4 qw.w7e: of 770m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at t0h g2lf- iivw-he surface of the Earth, estimate the total number of air molecules in the 2ihif-g lwv-0 Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrog,7sg8h 7 ml2jeajvf5gen 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 b0;-w w5drleh pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min.b0lh ;5er-ww d $\approx$    hour

  An iron cube floats in a bowl of liquid mercurnt86co 7mci4 py 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 gasolinex6g *d2:jkdla 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 f2y3a2 pcpb3oqs8l ; fqit 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 onto a glass jar at 2b :n2wrq 3;rnf0$^{\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 sta xl;/ y9nugdjwvik6 /,4 9hkjfndard, 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 charn;o7kexs d2l97eclz (ged, has a pressure of 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from the Earth i5y ygg6ifri;wim8 k 6.s $ 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 ik dvgp (c0v/kz+h.bae.zeu7 y3ai3 pc6exm:(s suspended against gravity by tennis balls thrown vertically upwardhv z0ck+/xak( . vpb:udya(3e7i gz36peemc . at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.0 dbf;:kj7x pf, + m+u1kbafpc*0-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it rex+b7p1fk aju bkf cdp; +,*:mfaches the surface?    cm

  Calculate the total water vapor pressure in the air on the followinl k cml19j9sug0x l 2n d(9r(zjie8yb(g two days: ubrx(i(yljk1( 02 99s9g8ecd n m jlzl
(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 osglxg*a1gc 5 r( nth5.f iron at STP, and when it is a solid deep in the Earth where the temperature is 20001cgr5 ltxh. s(*5aggn$^{\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 gayi 1zhq,j9t0y l j0a7bs at constant pressure, the coefficient of volume expansya,0jj 9y1bhq zt0 7liion 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 constanhvga i5 i6n /lj8:x+mrtly dehumidify their cellars to prevent rot and mildew. ir :i5+6v8jml/axng hIf the cellar in a house (kept at 20$^{\circ} $C) has 95 $m^2$ of floor space and a ceiling height of 2.8 m, what is the mass of water that must be removed from it to drop the humidity from 95% to a more reasonable 30%?    kg