Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic -m.yzu7t tum *6b kvf*table outb6k fzm7y.*-v umt*r Appendix B.

Name several properties of materials that could be exploited to make z(co.kv8 nhn-gpbest25 ,ci (a thermomet2pgi vn-8k. e (oz,t(sn5bccher.

Which is larger, 1 Cpzm 097f ufyj2 $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrih9ck/w vn2nf:um with system B, but B is not in thermal equilibrium with system C, what can you say abkhw/ 2fcn:v n9out the temperatures of A, B, and C?

A flat bimetallic strip cz 1ow.yr1a w8uie18atonsists of aluminum riveted to a strip of iron. When heated, the strip will bend. Which metal will be on thio ry 81ae81.zwua t1we 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 of4 nky5w wh,rwb1:fw- g linear expansion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a sim u71sn yvniw42ple thermostat used to control a furnace (or other heating or cooling system). The syu n71v ni42wbimetallic 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 set at different temperatures.

Long steam pipes that are fixedd7 xs+: qmwt5onq3-fk at the ends often have a section in the shape of aqdw7x-:k5o3stn q+fm U. Why?

A flat, uniform cylinder of lead floats in me, /ukowh,h vhy91(quzrcury 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 water, m xhc -rp4iz4f// l:cuthe mercury initially descends 4x/i4/ pu:zh-fcmrlc a bit and then rises. Explain.

A glass container may break if one part of it is heated or1wai p;v 9qpo;)l sdn+ cooled more rapidly than adjacent parts.wvp+nl;dp)9qi s1o a; Explain.

The principal virtue of Pyrex o. d/ .ft3olker*kywgs 8p(i;glass is that its coefficient of linear expansion *wk;(eod /8ios f rygkp3. lt.is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, ua hal 59t0nz)1yqsz7accurate 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 cau n36-5arykug8 hlylx8se its bottom and top to bulge so badly the can will not stak-hn5 agu6lrxy8 l 83ynd up. What has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its temperat qlxh8dt;h+)iklr s38ure increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules tk)rh 8hdsq;l8il3 + xwhen they strike the moving piston.

Will the buoyant force on an alu;um ddca8 6,cvdf1-co minum sphere submerged in water increase or decreased;fd8c- cov1u6md ca , if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theo35+zuf 5ns rhwsn-0sory and the relation between average kw0so5 sfh- 3urn5+sn zinetic energy and the absolute temperature.

Explain in words how Gay-Luss2wd.bzd1r p :sac’s law follows from kinetic theory.

As you go higher in the Ee ww kiw9t++v v)bfi0+arth’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object)8s;96cz ng *blxa. vzchtif7 must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the Earth due to the Moon’s smaller mass. Explain .sz9blcc itg6)a xf;z8 n*7hv why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What can you in .lbt.:0trjorr izg: k07o8r nfer about the molecular prr:rjrgit 8 nrolk.t00.oz:7 boperties of one relative to the other?

Explain why a hot humid dasr +sjnh4f5g6l .i9gqy is far more uncomfortable than a hot dry day at the same t5lsr6 n 4sq9g gj.ih+femperature.

Is it possible to boil water at room ,z6zco;k;rr eo-rm c4 temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the2 x -d;s p pss4l:fm1gw(,bmvo same but the humidity is differen spmdsf p4os (:bv;gwm2l-1,xt. Which is more dense, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator4mii u jv mn.)uz;9k2 n92nqbc cap of an overheated automobile en u9kvu4z2nn )im;q9i .jcnm2 bgine.

Why does exhaled air appear as a little white ip k1thfq8aaw w (u.um /c8:4lcloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram cope: 1lw 8x0injuper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compqgmdo )wr i;*;are to the number in aqrd*;);w o img silver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsius scalebsmyopyp0w qt)b;c k0n8 2-,.3 ileh c?pi-)30tqbbm w h,so.8ep;l0cy ycnk2   $^{\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 recorjw1txwc/la)4 1 b8lnh ded 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 al84 1lc ud(s*v ipsj a79wnjg)lcohol column has length 11.82 cm at 0. ndjcswa7i gl ul sv91)4*j8p(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 long6kg wxh9 yt4t0 (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 oln b nndkm./p w9ic9-8f wrought iron approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and January (average temperakp98i-dw9/ clb. nm nnture 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 axgefb5cl 77d +re larger 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 r7ex7 5d+bgf lcivet 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 . tkp, 0dye0lps:4eu xat 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 90 n lgfb;t9bm)o2rle in diameter. What will be its change in volume if it is h9emt lb; nfbgo2r)0l9eated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mLcu.l6 py2 z2 u -e2ce(j- k-)rqqiscvf of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL of water at sh(pcu7 f1 :an20 $^{\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 q4l az,2qmo)hme 36w m20 $^{\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 in esse4 p:20 (bxhbkqgk :vc5gf cpkkol.8 )antially one direction only, show that the effective coeq.2:kk0ag lp5f(x hc 8kvk) bg4bop:cfficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in bw bk)) 4jyxn,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 wi, fclbl)( ley0dth w has coefficient of linear expal l0ec )flby(,nsion $\alpha$ 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 isoecxcgops w5.3 xu,am5q,s5e;4*g v vc tropic 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 grang;xms//uvv-vq. 0 autdfather clock is made of brass and keeps perfect time at 1g/vqtmv;/.xu0 a-u vs7 $^{\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 insideu jk x78y ,tp(( +zg611phfa urshenn9 diameter of 0.140 mm. The bulb has a eru+ (a y 8zu p6knh1nf(7sghxpjt1,9volume 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 rpqqbld uqt h./; y761oadius 0.41 m is rotating about its axle on frictionless;d.1/ obt qqy6l7hqpu 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 j1f9os.y4 t,ya/dderdesired length when at 15°C. How much stress is required to keep it/d1r,dy 9 4tajyof.se at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional area 0.04;*)h )dh2h lo jmc8yxw tyqr.41$m^2$ 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 cx.+;u5ocb4qb is2j ufm 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 scalem,31gbxwy3b z:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temperature on the Fahrenheit sca ugeh;w rc7e.8le?    $^{\circ} $ F

  Typical temperatures in the interior u wghu43ct3kpjrk+l ;;u8gf 5of 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 pressure 1o9-v)a- sd +hdm jiuuand a temperature of about 2ju)a +ou--1mdsh i9dv 0$^{\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 ideal gas(p3k4 0z 4.;6qxb 9kvw6isivvoz .plk bagd5q law.    kg/$m^3$

  A storage tank contains 21.6 kg of nf6 ca af872pme*j upo,w,pe8 ditrogen ($N_2$) 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 cog4 zo zv.7u(ijjdn5.dol4 gk2ntains 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 s/ky e5i/ ki,eirr,(zwc f4;ad:j(fc 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 inskgd f6qs9i1( hide a 35.0-L container holding 105.0 kg of argon gas at 38sg f6 (k9qdih15 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg o2ws 5:wev31plr;qfu a f $O_2$ 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 alccmj 3qy1uvz2)q 0e1 b9naj/ir inside the balloon, which makes it less dense than the air outside. Suppose the volume of a ballo mcjn1)j3clybua/9q qvz 20e1on 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 15sc2 9c .bhb2;gabwj,n $^{\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 18.0 *o;ley2o6fhbfkct, /va7jo; $^{\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 c:azxbm/i m(;vff srau64v /,pi0j -u child’s hand at sea level and 20.0 $^{\circ} $ C. When it reaches an altitude of 3000 m, where the temperature is 5.0 $^{\circ} $ C and the pressure is only 0.70 atm, how will its volume compare to that at sea level?    times the original volume

  Calculate the number of molecules 8wh6s n 8 uvewz,u/lu:/ $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000wqmfqh7pvgx)o* -0 3 h L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) m,tl bd;zj1p1a oles,    $ \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 volum/* kc4gh7j,uyx8ultm e 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 3e0 msaw+i6b kyou inhale that were also in the last breath Galileo i0se wab6km+3 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 molek943 xzj;ey-wb uvzf ea,c.,s cule at STP? aw ;f ku43,zs9 zycvxe-ebj.,   $ \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 srdc2rnk/6p z/mq ffg5(v)*;vr rtb6) s sp0d at a temperature of about 6000 K;k2r*/c vmg/ db(6)s fqn0pvfrsr 6 5s)dprtz.    m/s

  By what factor will the rms speed of gas molecules increase ifp(+ l4g-z zfjp the temperature is increased from plf+z-j p(z4 g0 $^{\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 thee9 c 2t7;sc:napn 4 rhxlf8.dio ye51u following speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate the rms speed.f leprat. 5 42oixy ns:7dcn ;1hceu98 $v_{rms}$ =    km/s

  The rms speed of molecul jnp gt7m,2g4kes 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 consta:pet nt0n5 l-skz 0vri b4:4nsnt, by what fa-k0vepis n:s 504r t4lbtnz:nctor does $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given blx wvp 28lnjc9pk68bwu52 6 mqy $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixtgrykpsz4e . x.-r+kv .ure of two gases at the same temperature, the ratio of their rms speeds is equal to the k4e+-kxzgrpys v. ..rinverse ratio of the square roots of their molecular masses.

  What is the rms speeb ji+s8l2 m6e /n6kwcrd of nitrogen molecules 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 d 9 jkwbw*r k3cfr. nq.)m*gv1+3:facaofz7 mat 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance between nitrogecm67cj 4-epp mn molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speel0cs,ttawy) 3+jcaa5e rz 14fd of an amino acid whose molecular mass is 89 u in a living cell at 37 ja r3+wctlyctaez fa0 s4) 5,1$^{\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 azj 01h mu2t1a;92-nanueompi 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 u9 doz).xalz+ dfe/xp5h+ m)ebranium, $^{235}$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 pressurenf)wcz y)d6ql7j3vr9 , 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 is 0.01 atm and thedkroqz f4:pm886uy*0) 2m g jno n,bzq temperature is (a) 9 ,nbfop z)jyqrzq 0mmo82 kg64n u*8d:0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a day when the t6pj1bx*qep66we 91v: (e3ghp qjxgq xemperatureqwe1qx*x 1p6 hq ej6 6(pg :pejvxbg39 is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place w8cou: p:e 1rmltrsw1; here water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place inz69vu 4(.qoo r.wzn yn the mountains is 0.72 atm, estimate the tynrno4zv. .q w o9u6(zemperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day whoib7, +by5mzlt1 pnr7en the partial pressure of water is 530 Pa and the relative humidity is 40 tr+l1n77p5 m,boiyz b%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day whef,t8xj t4 ht3en the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximx,u1 0pmaqn-3jarl* m(i-juq ate pressure inside a pressure cooker if the water is boiling at a te*lauxm q3 mjpqj(n-u a,1 0ri-mperature 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 of volume 680d/ -6-vljmjwf $m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its deon /( zsvq;;;4 :tenmbok b+c-nat0dlw point of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine molecule (see Table 13–9 gvi twq4wcw:q+t*b d/ yl,3e4) to diffuse a distad3/ ww+clwq: tveq*9ty 4ib,gnce 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 rmjv 4me75tpm1vj11p surface of insects to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has cross-sectio1v1 4r t 57ppemmvm1jjnal 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 besqs+zrve;bg*k-2u d3en 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 measur7 2, 27t ryvnqb0rwg 1qrrl5pzpc h0e;e 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 waq-+ s66dz l 0yje3v + vbnnhv6-vrz4xps calibrated at normal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water and the cup a6bv3zenqd6y-vljzh+xsr0v + -np 4v6re 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 man.;;ja nr fswnc4+yf u7y balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the .y ;wfsr n;u7nj+fc4acylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.p+qfal8svl . 41 m, and height 2.5 m. Assume the temp +.qf4ll sv8paerature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about one atom pe 81nkdj6vh11 uazr +ajr $cm^3$ 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 avaitvkg v.y7d:*rlable vacuum techniques is abourvk7t vg*: .dyt $10^{-12} N/m^2$ 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 g;a z:8xde:bi L when 10 m below the surface, to what volume would his lungs expand if he quickly rose to tzg;bae 8 xi:d:he surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a speek 1v;u:ex z,zn(p oy;nd of about 40,000 km y,no;n1 (e:; ukxzpzv/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal+.i4 tkxedem ( gas is increased from 110$^{\circ} $C to 360$^{\circ} $C while the volume and the number of moles stay constant. By what factor does the pressure change? By what factor does $v_{rms}$ change?$\frac{P_2}{P_1}$ =    $\frac{(v_{rms})_2}{(v_{rms})_1}$ =   

  A house has a volume of 770-7l(hkh6nzug 46j9fkqd cq ne+k7la +m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at the surface of thq ()h9h l-bs-szt +yqwe Earth, estimate the total number of air molecules in the Earth’s atmosp+9hql- z- bsh)qtsw(y here.    $ \times10^{44 }$ molecules

  What is the rms spee- 2* 6(in rbhzvw0jkord of nitrogen 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 oxy/vuot,4r ar 6sgen used in a hospital has gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long wi/ourt4vs ra 6,ll the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid)p4 hx;mvqa/x +zmo: g 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 ngnvw 0fd /a+/at 0$^{\circ} $C is 0.68$ \times10^{3 }kg/m^3$ What is the density on a hot day, when the temperature is 38$^{\circ} $C?    kg/$m^3$
What is the percentage change?    %

  If a steel band were to fit snugly around the Earthih*(1qa/y isfe/ fci /’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 glaseg s8fxypb:((q2 xl6e s jar at 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length standard, adopte,pe+dtz g- s.hq k9 ptcq8mr kg:,e)k1d 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 of 195 atm79/:u )wf kdzsig( mxx 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 //q x md5zq*ptm1wh/9v)wtc a the 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 byz/oyiu6ru . +vwm/x 35hay. co2;nuia*f*mj z tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and u.f 2m*iv/ ;j yaxz3h iur+/ .u6z*awoncmo5y are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubble oy yh c- 3 d,;dgumnaqga+0is:+f 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 reaches the surface? ;u-aqshny im yc +:3, g0gdad+   cm

  Calculate the total water vapor pressure in the air on the follmv.gk2*b r9g 6uqpwj; owing two days: *j62wm u9. bqpv ggkr;
(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 i bxfznn:-l0*the density of iron at STP, and when it is a solid deep in the Earth :zb-x ni *fl0nwhere the temperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, for an kozokcj5g6nj6y 0y(2ideal gas at constant pressure, the coefficient oo6z2yk 5nj 0(cgyj6kof 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.