Which has more atoms: 1 kg of iron or 1 kg of alumipibk2ht0yh a , o hjgd x(;3qy+2s+wc/num? See the periodic table o+xyy(c+hkhgj2w0/ d,qo ips;ah b23tr Appendix B.

Name several properties of materials that could be exploi bka7 kxl/lv;h o*dph6,-;jeuted to make a thermometer ax;k/h7hojb;l-u e,6* pkvdl.

Which is larger, 1 C pia-/vg5.v 7gh(al bcam;f0m;ap j,n$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in thermal svwpv+)d (ulu:9ua56 uu1(k a ag6ulm equilibrium with system C, what can you say about the temperatures of A, B, akvua gvl ualw6a (uu1+ uu5s96()dpm:nd C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. Wh;8 v n9blut4uten heated, the strip will bend. Which metal will be on the outside of the curve? [Hint: uub lvn ;89t4tSee 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)wv:nn8fjygs:.34ge h6) k ufg8dae psion $\alpha$ 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 sios +40zarjw;8zs f3dv mple thermostat used to control 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 containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how it can be setdzz;f 0+ras3w48vos j at different temperatures.

Long steam pipes that are fixed at the e 6rvpuwb:ys w t5;p(6knds often have a section in the shape of a U. Why;vwurs 66wpy:tbkp 5(?

A flat, uniform cylinder of lead floats in meiwnd2seiu fn q417;; xrcury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is first placed in a hot tub of xy57uh g.0omp7j h +bzwater, the mercury initially descends a bit 7.0gyo7 zb5 +uxhmh pjand then rises. Explain.

A glass container may break if one part of it is heatz4+ g ijqwuh() (g3a2bh.ifdted or cooled more rapidly than adjaw h (f)bh3gu 2igd.(4jqzat+ icent parts. Explain.

The principal virtue of Pyrex glass is that.hcyup34kj3xuk: t/vyq/6vf its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain wp. yyvj /63fkuv3 xqc4t:k h/uhy this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, acc11 2 pwxevgw 31c9g.-. ffmp2tkjmfcxurate 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 anx e t 5:flgde e3gj0y;11nl:wgd top to bulge so badly the can will not stand up. What has happete ;yxlnd:ej3 ggef1l:gw51 0ned?

When a gas is rapidly compre 7+;by(zo/sqiw2 kw ikssed (say, by pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particuyzq;7bwkiis+k w2/ o(lar noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on/c+; fvm:y 0 j o4xfrh2fug*yn an aluminum sphere submerged in water increase or decrease if the temperature i* /fv4ry uxfy0n2:jhc; ofgm+s increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and the rvy+vtxckylz 43squd- :b r 43*elation between average kinetic energy and the absolute temper+t4scdyz: -rky3v q 4bx3 *vulature.

Explain in words how Gay-Lussac’s law follows from kinet - o:v-tvb 3js,mjp4dlic theory.

As you go higher in the Earth’s atmonc )dv1hq -spjwm+uo*2:a7 nn sphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth rsb)ag8qow k13 3u8 +zyjltwuy9 1r .krefers to the minimum speed an object must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what81j+.ukw 3qr)zb 39sygkyolw au r18t it is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more qui gqs4/u+ ,girackly than water at room temperature. What can you infer aboutgu/i s+g4q r,a the molecular properties of one relative to the other?

Explain why a hot humid dayc44r.)lu,h jbiub9 gs is far more uncomfortable than a hot dry day at the same temperaturu,49.bih)l g sb4rj uce.

Is it possible to boil wu lb/impk.3msan 3.p: ater at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air tempeeghft*vg:opx rb 5ut5;):s w4rature is the same but the humidity is differentuxtr5 ;e:4vh*gs g p5)o ft:bw. Which is more dense, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radil1t )cxbw3w + /v7, dv,qgz:mk umchqku1/q;xator cap of an overheated automobile engine1d cv ,qk );/qx,bwv31 k/+h ql tzmx:mcuwug7.

Why does exhaled air appear as a little white cloud in the winter (Fi+js iq9il9nki jp,u/i0qny 2/g. 13–28)?

  How many atoms are thnwdf5m i2 84iiere in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold rin 6s0vbno)f6.b0hgd beg compare to the number in a silver ringgod6he 0.fbn )0v6 bsb of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsi:li :d6h83l.h axzrrsw-il l4 us scale? is-dlrll hrh.8wz 3:a:xi l64   $^{\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 thlfp/and+3e 0f ml.f8emperatures 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, the alcohol column has lengthi2 pul p v)v/u( xu-r35jfh/wl 11.82 cm at 0.0 /hlvvu )p(pu/-lx iw32 5j rfu$^{\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 o-d(j4t2j/ ) im ns4,pgpv siucf slabs 12 m long (20 $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

  Super Inva$^{TM}$, an alloy of iron and nickel, is a strong material with a very low coefficient of linear expansion [0.2$ \times10^{ -6}$(C?)$^{-1}$]
A 2.0-m-long tabletop made of this alloy is used for sensitive laser measurements where extremely high tolerances are required. How much will this table expand along its length if the temperature increases 5.0 $^{\circ} $ C? Compare to tabletops made of steel.   $ \times10^{-6 }$ m    $ \times10^{-4 }$ m

  The Eiffel Tower (Fig. 13–29) is built of wrought ironz /xpi(8c, gr, qdek4o7 v(gal approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and January (average temperaturdp7kvx ,/c(i ( 8,aoggqe 4lrze 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 largers-xr,wf(ab4z0)i6, hvc uvo i than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cmuoazs4,i6 w0 )bhr-xfvi,(c v 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 azfv;ax3wg7 hiid2)y (4bg7sm t 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. What will be its change in volume if it mvmchw2kc -/4m)q;znra6g d- is hh64)mm/d mqvr2w n ccak-;-g zeated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL f jk5puhoe(8)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 5psu2128f t gzm5.50 mL of water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to be placedfkx :c.;bfzq78x io1a in a ring made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, narrow vessel so it can expand ij z/b lr ioum)*df(1ndwu2lo48q:h l,n essentially one direction only, sholo, / j*nmudd8r4u 1o hfq2i)(:lbzwlw that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the densityq e/ mh)u+65t* vbz, 2 1kf:kilpgdkwc $\rho$ 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 ply5 v0zip3qexf99 j a:sate of length l and width w has coefficient of linear expans3q5ei90apz9sfjv xy : 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 -kx2: 1 uos4pousru- kbw4nz 0solid, $\beta$ = 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 ukvzi/ .bihh8a:s8/ xkeeps perfect time at 17shh 8//xai8:izuv.bk $^{\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 of 0.140 mm. The b0j1;1j u:k kz,xw1x lz:w+bflk4rclbulb has a volu:xzjkjbx :14bl01w k+ukl w,cl;r1zfme 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 (2su6a .rjurxm)h+w1jqs k-vi4 :e u gwheel of radius 0.41 m is rotating about its axle on frictionles+u r hr)svsq1iwkuau-2xgje4: 6.( mjs 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 t 3*unrm7ut1/t/r5*d ed 4 zuzakpqn *qhe desired length when at 15°C. How much stress is required to keep it at this length ifd/m37u zr u5*q/e*q*tanpdtk1r n4 uz the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel l4)y + r pr9vfv epvttq)es8vrj v4.;vih5.:hI-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 b5clh.ov.hy rft 3,;ayacxy+-*pou0 134.122 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 Kkbd:b-,)-nisys k xs2 elvin 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 wha 36wrtagxx 4nb1;4j;fxw * gayt temperature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the i4u. ;usl) mzfinterior 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 atmcbpm*uos94 6l xz/ro9ospheric pressure and a temperature of abo / czx99b4plo6sr*mu out 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 the l:tl2k c i9pc)ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitrog:t-j h9vx dpmogrrxj,f r:(bapw 208 4en ($N_2$) 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 containluca-/rp;an8 +ay a +bo7*gels 18.5 kg of nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gas is at 1( y 1omr mvqtta3ar528*tdm/e 0.0$^{\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 yir uo) x0bq;xg- ;(qhholding 105.0 kg of argon gas at 38qyrgu0 ;q (xi-ob; h)x5 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 ol*9b,rf hoy0,ao5gg 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 the air inside the ballo5-7ao 6 fcdotvon, which makes it less dense 7f5 otcv-a6dothan the air outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air at f39pb ousoto 89h2mg; 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 0hbhv8ggyts0 hms)dbqd c u.g2; 6,2f18.0 $^{\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 level and 2 oxg .fow.5zqy7r;n.n 0.0 $^{\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 .,/tu.iyx , 7vcz us0f(utws pmolecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many k3;, e r6ygq6yrq*k,h bht0m - hf)bwtmolecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of) td;ot*xdh )i8-epn g (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 volume9atl*51u 98n-mc( yl8oixcgjv maj2v 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 aiaswkurzd(0d4s ps9 8 )i.ndqabc. m58r are in each 2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphe (p.daksuar q swz5dd89n c.0mis8b)4re is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average transla v h;jidmdgm;)sv w8c 03rzfxm 351ch5tional kinetic energy of an oxygen molecule at STm3m 3w 8 dfj1mvz; csrgd05cx5;h)hivP?    $ \times10^{-21 }$ J
(b) What is the total translational kinetic energy of 2.0 mol of $O_2$ molecules at 20 $^{\circ} $ C?   $ \times10^{3 }$ J

  Calculate the rms speed of helium atoms near the surface of the Sun at a temperajndtl 0trkf (u*ztjmaq+i147a r 2qy 0k/+j4i ture of about 60+2qi1 (d0k4+ijzjaturfql 407kay rn/mtj *t 00 K.    m/s

  By what factor will tb) (y.xn*g ui1cvoy 7gp u9 s3ip4rkw1he rms speed of gas molecules increase if the temperature is inco ps gy*1 rigc.3x u(y)pui17b kn9w4vreased 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 folleb a60ld5nkw3cs5lr )owing speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1klwnd c e055rs6l) b3a, 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules: +tonna6 7- two;lust 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 cow xk58a.zl 6pknstant, by what fact5lz8wkkx . a6por does $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given by b s.282cwpike$v_{rms}$ = $\sqrt{3P\\rho}$ 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 thvdp ql+d+ k1 :ifo7.uheir rms sp: +khv+i odq. fdp7ul1eeds is equal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules contained in an q dy; b6 cyzwk.)7l k6e6.usyf8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms spe (r wqzifl7e9;x4bvmf k0 /u/yed of an 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 distsb84c 4em7 bgvance between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an jej1jrc6gj75 amino acid whose molecular mass is 89 u in a living cell at 7j1 6jjc5r ejg37 $^{\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 can5 , os;;5ccb eaej *62fa;t.csvvjpbq 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 uraniuos74xa*h gddv8ip2*i-wgm qx: d e-*vm, $^{235}$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 phas bsy)j d-jo6y i;l15pkes can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure is 0.01 atm and the temperature i:1tujk: m+oqn4kvbv 00 c xpd-5f3 oucs (a) 90 ovcu1+t p x dom3-45nf qj0kbc:0uvk:$^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a dayh+ o4d oq+q*u ryt7)fq when the temperature is quq 4fh)oor*t+q+d7y 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where w :xhgg,w du/:aater boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mouu :fb;j 6y7z r,js2enantains is 0.72 atm, estimate sneu6za: j2b, ;fy j7rthe temperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the parbe,fly;bn1+4e6q lctpg 2cz5 jro 1d) tial pressure of water is 530 Pa and the relativebz+oycebdglf,125 pt 1;qlc)r 6ejn 4 humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day 6 ql7i 28c,,oedxqid:*zbq+ d3scmgvwhen the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water is boildo0jz eh8i.,l ydo83uk; g8sq6 lt)pying at a oqp)83y; ld e6l8ko0u,8.hi sj tg zydtemperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room ofuhul+ 4bhz69f 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 o7b 9/edsyk smxpzc2-6f 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 diffex m o(1k7 jnj:4yek*i8h/gde8hi2 mruse a distancm/iyhki(j8n8eh ej: rx *1 47me2gkode 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 insectsft./ qntfttd4c b4 8ib w63;4teggr*o to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has cross-sectional area of 8wt46cgb e;btg/ iodn rf q44*tt.t3f$ 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 beennnw 0s +6koo+t:k2ktd 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 measm vl.est.g y/lkqbqer9-3+d 1ure 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 axmpk 4w/ +p2stt normal room temperature. How much error will be made in a recipm2 psx4+ /ktpwe 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 q plzj 2vg)73;o 66knl2j ((ch)kswoz vsgzh/helium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What frogqo3snw zj hc))l / kgz;kv6z7js 22(p (6hlvaction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.1 m, 270;r, v u65suaztfujo;bb,w+ oms y nand height 2.5 m. Ab,r;0jts 5sav 27wfbumyo;6u+ ozu,nssume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density a8m+jce28 6n- 7fxadhvr w: ooof 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 afh vrg4- f4hc.ttainable using the best available vacuum techniques is aboug- 4vh4rf .hcft $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fills his lungs to full capacity of 5.5 L when 10 m be*f4ii xntm6*o low the surface, to what volume would his lungs expand if he quickly rose to the surface?*nxf *tmo 46ii Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s mgkra);3j es5lqh /d8/8br i :l-wd jbatmosphere at a speed of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose ms l5d3wbib/r8kj-)h qgd er:;/8a ljof 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 increasedhyw9*nj8vw2ml2i*e j 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 volumehd00+h9j rn1: vqvc. nujrke9 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 atmosphera(oqjsmn8g:v*zvb. .xw3 i b ko6z;x/ic pressure at the surface of the Earth, estimate the total number of air molecules o(.;j/vz*8.bk: wsx azq3omi ngxbv6 in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitro blzzn( 5 (/i z//dvyofn;wl)fgen molecules contained in a 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygen used in a hospital has gauge pressure x5c: v5gl m;do+vc3cu = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if v:u3gdoml5 c5v;c c x+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 mercury6 cr; alz1pp.c 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 a hxtyg4r1baot28 )m8w*86rqsa5og rkt 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 Eart;ekrz-:kgcdr 0-qm b0rc2x1tfx3m0 vh’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 96vkv;iu.g- dt hb d zpb0*6jvsm3 vt:at 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length standard, adopted xo jx.dv, a .-sc1sw1ain the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully charged, has a pressure of 195 atm:rwn u6lm gaq8 l.*+cm 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 is z2z(i /.vfeqx$ 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 throf p1vi9km 2r+wwn vertically upward at it. How many tennis balls per second muskwir v2pfm91+t 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 3.00-cm-di ;0z-i- nkkeqgameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the tempe gi;kq- n0-zekrature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water zxy2nf7l )ds qj9.gm6vapor pressure in the air on the following two days: 9jnq7fsg d.ml z y)x26
(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, and when it is a mg dbi-pz r1cx01;b 8k,0nioh solid deep i1rkp0bbxdhmg -z;in,i0 8 co1n the Earth where the temperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal ga+vq3 :ssr.mkbs law to show that, for an ideal gas at constant pressure, the coefficient ofkb.mvsq+ 3r:s 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 cqxj.;zqltzk0x z3*1 z )j .aband mildewl1ax0 j3.;c.qtzbz) zq*zx k j. If 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