Which has more atoms: 1 kg ofcir)h9 )s utg+ iron or 1 kg of aluminum? See the periodic table or Appench9trus+)i ) gdix B.

Name several properties of materials that could be exploite;ze;(;w xfldsd to make a thermometer; ;zf w(;slxed.

Which is larger, 1 Cfe.7oz 1ku p8ko es8 n(zu3qk2 $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermaf5,e,cxnt 2t 8b*aaczl equilibrium with system B, but B is not in thermal equilibrium with system C, what can you say about the temperatures of A, B, an *e,, b c5a2tnazft8cxd C?

A flat bimetallic strip consists of aluminum 8e5mqg:o i.tsn,7 pvhriveted to a strip of iron. When heated, the strip will bend. Which metal wisv,ino.p qg het87:5m ll be on the outside 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 linear expansionu yi-32j(i,ihpma.p tl-:6 xdz bee. p $\alpha$ 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 x z 1v4ofx7ps +z6phn*h58b lj(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 containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device bl1 zoj 74v+f xh68 5*zhxsppncontrols the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at the ends often have a sectin0eltks c)(*9e uih174 pi vkion in the shape of a i)(t0e1sl *ch iv97 ke4knpu iU. Why?

A flat, uniform cylinder of lead flf(cm;*7r5 *qvfba qkx: uo4 epoats in mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-gvmia) n)rww: ;e 7b)st0k(oex lass thermometer is first placed in a hot tub of water, the mercury initially des)n0ak:v etm7oe)iw) (bx;sr wcends a bit and then rises. Explain.

A glass container may break if one part of it is heated or cooled more rapid c,4e2ll3kc dmmdd9 w9i-*gtxly than adjacent pgx3*d,i t992wecc 4mkmdd-ll arts. Explain.

The principal virtue of Pyrex gmshj/6 62e2r .m qfwvalass is that its coefficient of linear expansion is much smaller than that for ordinq6 rf2amjh2m6 we /sv.ary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clomtmlpv u)x7qnl;j5,li)2 i .voffp4*oql p4*ck, accurate at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and top tos**2p i,jb rsg bulge so badly the can will2rs*b pgsj, *i not stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a pim y0(h m/)f;md-o) xfgq1 usclston), its temperature increases. When a gas expands against a piston, it cools. Explain theseflc f/ gdyxu01()mh )mm-so ;q changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged in water increase ors.wxpf xn31 h8 decrease if the temperature is increased from 20 .8w1hxf s3xp n$^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from fjle (thxll u8h85,2d kinetic theory and the relation between average kinetic energy and the absolde ,88j2fht hux l(l5lute temperature.

Explain in words how Gay-Lussac’s law foe. b7rf4 czjco4q;*zsllows from kinetic theory.

As you go higher in the Earth’s atmosphs:4o/ nqj.lqyere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object museaqu 12ar o km(bn gw99/,(teat have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the aaorn(e mb uek2g/at9,q9(1wEarth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates mor;f( d(r7o lyrce quickly than water at room temperature. What can you infer about the molecular properties of one (flr;r7o y( cdrelative to the other?

Explain why a hot humid day is far more uncomfortable than a hot dry dayf 6yu0.- is6 xovo.hti at the same tui..y hv60t6-xsf ooiemperature.

Is it possible to boil water at room temperature (20u 3nh5pj6ho oa,h n xm(6skc5. $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the sbj hed- ,z57wj3:ho sxoi9zn7 l44ulckt-ss- ame but the humidity is different. Which is more dense,nbj4l 4oo7clih w-tks: , u-3-7d5 sezsj9hzx the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an8 3 xspw97bqx:k r;xva overheated automobile engine.xxpbxr9qk 3 ;w8 s7v:a

Why does exhaled air appear as a little white hadl,dn*hq 7 dwr0ogj7/ ;h(vcloud in the winter (Fig. 13–28)?

  How many atoms are there 11er6v:zi6frmb3c::ip(f ol g xnjq4 in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold llh4 tf1lf,4./ l qbky(gu4or ring compare to the number in a silver ring go1 lurk (fl44 .ltq f4,lbhy/of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What :l(jfy lb+mqu.6:ufjb;*qrzr* +eol is this on the Celsius scale?*(bu::erl+bm+ u6o jqljf lz f yq;r.*   $^{\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 temin-f f+i *z+wdvc1: xpperatures 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 therju i)56zqd9pp/ m4eyi mometer, the alcohol column has length 11.82 cm at 0.0 / 9)d54yjipmqup6 iez $^{\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 lvrl)dt n,pwif00v0 g 9ong (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 approximately 30ddz0/8 we hz7j0 m tall. Estimate how much its height changes between July (average temperature of 25°0zjz 7h8/ eddwC) 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 lap6psdw7 1cs1d ch*ad lx(u;9 co h0-ekrger than the rivet hole are often used and th1 d cwe 0hlc*p19(x7skdh ;-dop6scaue rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be 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 ato *,(d;y ivc rtjj+jk1 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 ink : +;)rwttgf, tvvv)t diameter. What will be its change in volume if it is heated t;vr,tk+gf )w )vv:ttfrom 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the bre,e*smze+. ,2miu vgslx+nu+h) vy; eim 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 55.50 mL ofth qnz 0ef8s(6 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 made of iron. At 3 ey(j-a* goi;iayq*p20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, narrow vessel so it can expand in7qqb/fqm2ojuc7 myc6 / u)28adu8wrx essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to the co/2 7xcd8 muf26rua uqq 8j)wbcy/7mqoefficient of volume expansion $\beta$.

(a) Show that the change in the d( ei ti5 3v4f8efxnzl1ensity $\rho$ 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 aq6w0j0 9(:sh9s uaiir0 h vxtcnd width w has coefficient of linear expan c0:vs6 rhiq90t x w9ahsi0ju(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 isotroov- j+ xl9urn:pic 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 t hf2we*f*l:ql f aougv-86.eclock is made of brass and keeps perfect time at 17 e.ugw8lvqffe 6ho2f-l**at :$^{\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 diametebs/so/( z nh0 +nug(j-gzk2ht r of 0.140 mm. The bulb has a volume of 0.zjh- ks g0/2ns(b/ tn+o(hzgu255 $cm^3$ 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 wheere96) w sg;obml of radius 0.41 m is rotating about its axle on frictionless bearings with angular velocit;9 mebwos6 g)ry $\omega$ = 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 +ju5y auli5 4tdesired length when at 15°C. How much stress is required to keep it at this length if the temperatu5uy4ul +i5jtare increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steseu 8irhw:-5ms0l 2nihl0z8sel I-beam of cross-sectional area 0.041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 134.122 cm at 20p cmsmj2h+ qiitu.7 ne8fe 6* b;(vpx*$^{\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 temmv9ih l.4 qy:pperatures on 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 o zp* j.ivjx5 - voi*gof1bh qr/3qv)/hn the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the intxjt;k : m)tb8s-p.c cterior of the Earth and Sun are about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

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

  In an internal combustion engine, air at atmospheric preqjcze)ld tlv-mw9s.-01rva34-t f o d ssure and a temperature of about 20t-l.mrva9c -q0 dl3ez4tdj ovs)1- f w$^{\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 udw a,s e+l0 lsm.t 5-om-zt)qant.3 csd5ug:e sing the ideal gas law.    kg/$m^3$

  A storage tank contains 2)yqh j;;r9f:5wqdw sl1.6 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 nitrogeuzkm l(0q3(03wem lg(v8)ypy n ed;ukn ($N_2$)
(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 a a 7kess;q4dp/xt+gh yq/zwjnz 1l4;2t 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 10pgq) lo5kz*zf7fiy k8iv1f1 kp72 ow5 5.0 kg of argon gas at 385 1y5f 82iolo1wkfk7i *)p 5zvz kfgq 7pK?   $ \times10^{ 8}$Pa

  A tank contains 26.0b)5g xr-bcie9 kg 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 thpv6: e (fxm2usikt+k* e air inside the balloon, which makes it less dense than the air outside. Suppose the volume o:6(xe mkv*f +kpsitu2f 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 airxdd8uzo7y 4 9c at 15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at 18.wieg4w ps3xc32 oon) (0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand at sea levr+-9.4q-* af5biwn jk e llcmael 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 molecules / -iybf 1t sl 1ri2c6e;qcuah* 1p;7epb$m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water aizz2jsu: wx iqk fm)--61-t ib+d0 awwre there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (g2s4n 2oea-x:r7j(qg;g qwz qa) 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 volumtm( o/ huqoqalcxipep -:2z/45 gdb(7y30pe ke 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 i)-+yq+*fh*(s tvf ufl zrda: hnhale that were al-s valf:qth + )*+ry(f *fudhzso 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 kinetic energy of an oxygen molecu5ew jz 5c+h-iple at STP? +zi5p-ehj cw5    $ \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 atzad+3wp8 p c41ihu uf.oms near the surface of the Sun at a temperatu3 .c1+fa4wuh8zip u pdre of about 6000 K.    m/s

  By what factor will the rms speed of gas moleculeb9 4nx -7njg7t,dmduks increase if the temperature is increase9b7n7 gnkdt um-d4,jxd 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, giej ryb wxw+v7-z7/1/bje g 8fyven in units of km/s: 6, 2, 4, 6, 0,-g e7/wj rx 81bybzwyfev/j+7 4, 1, 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of moleci1o fvh6q 2(8w*j qnazules 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 volume is held coi2i/ebguj3l :k2 gzb;nstant, by what factor doeb23l:b;ge k z/ig2i ujs $v_{rms}$ change?   

Show that the rms speed.10g3 qm/kqu.dtd ,,vm dtzg9 owsju, of molecules in a gas 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 mixture of two gases at the same temperature, the u6 gn;ek):vpnoq2m/cratio of their rms 2 nokqn:/g;vm) c u6pespeeds is equal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen mole 7c * qy8avtm)o7p7nnjcules 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 oxygen molecule fr 7labuu/05mb na:u)a( csd; 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 distanceavxtvo-9a1 * r between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u in alhc9ffi4 32mi8laolmz75( s u liishf8caiz mu2o 53f7 l9(lm4lving 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 jhdyp* agp6-* 6-3zvf8jidduP of a 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 uraniumoojn1qro k;,zr hlw4 x :2+em6, $^{235}$U and $^{238}$U (the superscripts refer to their atomic mass), can be separated by a gas-diffusion process by combining them with fluorine to make the gaseous compound UF$_6$ Calculate the ratio of the rms speeds of these molecules for the two isotopes, at constant T.   

(a) At atmospheric pressure, in what phases p(u:9ef oecy,x2ibhe9 ns):ak,z8 bncan $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure is 0.01 atm ap0-k+0oqur :hf kb5hxh.);m5 jzrxs nnd the temperature is (a) 0 umkozhj frsh5 rn+-.p;x hx5 qk:0)b90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity ibggnlf2/ 8qp i/*j4res 50% on a day when the temperatu8bpq jli g re2//4fn*gre is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boils x t(,ot12 w)njr7o uk+vz:spv at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountaymq-.ek)ws61 /h n)j1gxcd mjins is 0.72 atm, estimate the temperature at which mcjj1) x wg6n)ekqm.h d1 ys-/water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure ofj; 7lhdnvv* 6mouw0( j8pdtn: water is 530 Pa and the relative humidity is7 njuvn;l d8 wjto:d*(vm0p6h 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the t;roq2 i0yw k. zdk.hhygmx ja.81b+g7emperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressur (ul)gl j,6seke cooker if the water is boiling at a temperature of 120 u)ljs6ke , (gl$^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room ofl5ha-- cbh)i2u pxj n5 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 f0 c v-f-em;0xhb nqj;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 1b t3k b;4pbnf( szg, no.rgr3+3–4) to diffuse a distancez pnb fr(b.;k+, gsngb34o3rt 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 ics 34-q4 xxtaqjn8b42zp /1cnfm 7y oqnterior through tiny tubes c-3 xzj 8s1ncaqn/pqf qx2ty4 7cmob4 4alled 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*ed62.off i/ brhwt l;een 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 measurwvuw 7/1: v m:mxd-h4 nwnqg4ee 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 wmj,3derrm -t5 as calibrated at normal room temperature. How much error will be made in a recipe calling for 300 mL ,3- mret m5jrdof 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 ).jm;o/t1m a 0;bcd min0o mtjcr.b8a balloons have been blown up 0ccb;nmt.1rmo )tadb;j08 jmo/mi .a, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules *1*kg g jq 3d(njgiv.yfap27d in a room of length 6.5 m, width 3.1 m, and height* *ap7ig3f ngjq2.jg1dyd v( k 2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density o1kurx- x.y .cgf matter is about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best available vacuum techniques isnpyu+k *8vt mk i63q.l abov t*p+.y68uk3l m nkiqut $10^{-12} N/m^2$ 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 mi/m 5;fu- ljubelow the surface, to what volume would his lungs expaum-i5 lfum/j; nd if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the g s*8tp lp t6+wi(q2coMoon enters Earth’s atmosphere at a speed of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with thpc6gqw+8pt*o 2t ls( iis 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 an ideal gas1hhl5tb ;8 mas 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 of fr z/v0e-yga9770m$^2$ (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 atmo,e cgyi p3j ;r9dhse92spheric pressure at the surface of the Earth, estimate the total number of air molecules in the Earth’s atmospe;g9js hcyp2rei d,3 9here.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen a.fqmq(2 ,1vaw mki 7nmolecules 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 pressv58law hp xiz5lo8u h)6.6 zukure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constan k vo lw6u.8uzl6xh8 )zai55hpt at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl o fcr ;rrv h75ha:3orwc:c02mi f 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 atmu3/x x p we:6ab 8jtrxb1,. :ei)qf l8a4cdao 0$^{\circ} $C is 0.68$ \times10^{3 }kg/m^3$ What is the density on a hot day, when the temperature is 38$^{\circ} $C?    kg/$m^3$
What is the percentage change?    %

  If a steel band were to fit snugly around the Earth’s equatou y5 oq2v:w sotwov;8-r 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 gla uc+twy7j;d )ass 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 standarmu1 b.uj k1qdlep)t10d, 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 of79h4- -c7xfpmdlr x ak 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 .4xrb,gmf;zgfzu ;z :dl fqr 0e*kq+,Earth is $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennis balls thro1yr/65 bx:gbxpjek 2own vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they h/ beo:rkx1bp 5gj62y xave a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3dqfti)( . frm+.00-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 theirfq. tf )dm+( bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the aos)zb4m / j4wd(lod,o ir on the following two days: oljwsd ,)o/o4mdb ( 4z
(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,7 w:dk5,tv ikt and when it is a solid deep in the Earth where the temperaturwtiktd5 v,:7ke 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 an46mn s 1bxhv/ox* 0ktv ideal gas at constant pressure, the coefficient of volume expansion is equal tov/*0 41x6ost kmnxvh b $\beta$ = 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 cel8oqqa vbzs*r5y w 1 /nrf:7k3zw)qns.lars to prevent rot and mildew. If the cellar in a house (kept atzobqqzrs y3n8v.a7/1rnw s:5 )wf*qk 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