Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodiz5 5p16 kayah0e* ngdoc table or Appendix *eo a51np 6gdyah05kzB.

Name several properties of msgz 3wnxgnc4 9(9dz1h aterials that could be exploited to make a thermometerd1scz g9w4 h9n(n3zgx.

Which is larger, 1 C 7q*8mk4a)o r0 ;f(x; vj jvd4z vc6dztn;vfjn$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B 12ueu -mecwr5is not in thermal equilibrium with system C, u-r 2 euwcme51what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a st8vjs5bvb;8 5u a2;o*k dqewae rip of iron. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hint: See Table 13– ovakdb 5 ;;ev52e8b8*wajuqs 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 ev25sc ;p,zqonq v8 ., 0lpavnhxpansion $\alpha$ 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 diagra m3yl nmv z;1yzk-r7c,(ob r)tm of a simple thermostat used to control a furnace (or other heating or cooling system). The bimetallic stripmoyv3m;rb zl 1cyrn- 7z(tk), 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 ,v( nc s9pk6e74ivgxufixed at the ends often have a section in the shape of uc(e 6vx p4gn97skiv,a U. Why?

A flat, uniform cylinderol. d89knugv7lb2( kx)ob; ta of lead floats in mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermomeo99o z,5y vr db0f7hfi g(nu,fter is first placed in a hot tub of water, the mercury initially descends a bit a,f df o( g 9zn,0iyfbo75hvu9rnd then rises. Explain.

A glass container may break if one part of it is heated or cooled mk )st qp8i9-osim03em1uh /tv:3 x oidore rapidly than adjacent parts.ou ht)-is:t8vpm idi/k x o3qem0 s931 Explain.

The principal virtue of Pyrex glass is that its coefficient of 44 dpyifiacv7/o l+-q linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resista a/qlo7y- ipicd4 vf4+nce of Pyrex.

Will a grandfather clock, accurate at 206kn3vweb9 u7glll:rt mn4ac*te )+*k $^{\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 (cowa l4(4nbujav* /r top to bulge so badly the can will not stand up. Whatn /r4o4(cabjw ul*va( has happened?

When a gas is rapidly vvw1qbdri;392 3cdod bwt y2qb m*d/8 compressed (say, by pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperat 8qd1q3d bd39 vmt; *bviw22ycro/d bwure 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 omc7p 4za )nut;y 2;yylr decrease if the temperature is increased flty;np c2y; m4 zuya7)rom 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and trw 0 d9hpg ,i:hjmn/x-he relation between averagehg/9 ri 0x-nhmw pd:j, kinetic energy and the absolute temperature.

Explain in words how pu,.0fxi9 ci vGay-Lussac’s law follows from kinetic theory.

As you go higher in the Earth’s atmosphere,m4rb v vz3eizki7)5*i g-yg5e the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum sehdyfa j0iwi(88b9p rm5xe 13 peed an object 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 why the Moon hap1w ymre8j 5dehia(b0fx98i 3 s practically no atmosphere.

Alcohol evaporates more quickly than water at room tempp g3ca(k x+8ekerature. What can you infer abouek3p(ckg a+ 8xt the molecular properties of one relative to the other?

Explain why a hot humidga apzx0k2)p8 5f9hp t day is far more uncomfortable than a hot dry day at the same 5kx)0ppa9ap8 fh2g tztemperature.

Is it possible to boil water at room temperature (2 wa p hqh-0avz9u8hm810 $^{\circ} $ C) without heating it? Explain.

Consider two days whjywdkh7cq92j1 u,xma9o *wlp31tc -ien the air temperature is the same but the humidity is different. Which is more dense, the dry air or the humid air a tjuc cm-1,3whp9i kjw q lydx1o7*29at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an o /on7*e2 pr 8q4l wp3(n6qvnhde8miwcverheated automobile engier2n6( 4 pwnohi7*pv 8c38n dqml/ qewne.

Why does exhaled air appear as a little whiyrm0) luecu ,o6l9yf )te cloud in the winter (Fig. 13–28)?

  How many atoms are there icf h:m4n/x0yun a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gokgmkb+izk20j0 r mnau1 +8 s7bld ring compare to the number in a silver ring of the same mkkrbg2s mz7+8n bi00+ mkua1jass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Cef6 cokk613: yqa0aqbj p1 bn*ulsius scale?6 qqa0 fn:16ubyocj31 a*bkp k   $^{\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 temperatw:3lnut +u/b4ypf gc)c0g. iuures 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 alcoqlzl:b6u3 *xnhol column has length 11.82 cm at 0.03z:l 6nqu* blx $^{\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 slabss7b8*ycf vvs8-v(vc8b0xg v+vm u; s l 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 iron approximately 300 m tallp2gtav8d x9*+e oad4t . Estimate how much its height changes between4 t2 8aed+d9pxat gv*o July (average temperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, rivets that are la* 0vdvo )hrxi:rger 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 cm in diameter is r*ovv: 0hi)dx 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 waterwl4 n uul,6s 9rxsjpkb(t(68x at 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 volumeutl/zk2 3qw+wzmt9 mauqy *.0 if it is h.w3yaq 2+uukt9m*t z /m0 zlwqeated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to th8y2 / 9onblcu.j jrkv;e brim 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 5w(v l()sj(e cm5.50 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 placed in a ring ytbzgkf .6 *(xe tzob6pb2(s 6made 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 in es nxtyu-u*).0nbeca(ul) k9f- )dwh qbsentially one direcbuwnn -ea))-(b.h 09u)kuld*tfq xy ction only, show that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the densiti/01dz( d;kld l zdwu3ke bkhc9v2;,ty $\rho$ 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 prbm 7: (y0iw9u/1nr e eddwwp6late of length l and width w has coefficient of linear expansio7ynre (6:ie bdw9wdrp0/mw 1un $\alpha$ 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 isotro orvxe-qdf;1;i: fji,kb*r m/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 clock is made of brass and keeps per :;og(nnxi,y cz)tjh:1or 0j afect time at 17h :o:nt1jr;ox0gn yc,ji a)(z $^{\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. f+ta-u01 4qt*k03 raqcrbkcm The bulb hafcmq1q r43-+0btckr0 tu* kaas a volume 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;rm+uv do*j5 jr4tszpf z 46,e radius 0.41 m is rotating about its ax*e,5rjp 6;4fosru+djzzv 4 tmle on frictionless bearings with angular velocity $\omega$ = 32.8 rad/s If its temperature is now raised from 20.0 $^{\circ} $ C to 75.0 $^{\circ} $ C, what is the fractional change in $\omega$?   

  An aluminum bar has the desired length when at 15°C. How much stres nfgdrhmj z(wko2 -*91s is required to keep it at this -drfog *2mhn1(jz 9wklength if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional aw r)6x u v 9/89f22babsnh8ei/xgcodhrea 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 a,fcvl yq47yqp 0yu lq + de,xgo9nk9y8gp s:)*t 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 s7qivyh94n w (kcale:
(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 Fa8 p7zp trz4md;hrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth an fhhmn atb 4)5mky3-z5d 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 pr+kkuo /8fqg zt74;lwiessure and a temperature of f;/+ z8go7 kikq4ltuwabout 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 ideal gas la jl),87gtr pv*jf ibp; vzdx 0.hwz;)aw.    kg/$m^3$

  A storage tank contains 21.6 kg of nitrog0nkuoo9;*ojf en ($N_2$) 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 contains4yi5mc t) tq9+ qk6ymph;x tdkwpw0(+ 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 heliumg b6oobt96w5t fecih ii+( r83 gas is at 10.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside ar,8x h94:w dptavnm+ ni)b9flgsxk. 71mc er( 35.0-L container holding 105.0 kg of argon gas at 385 K8 7nmx ,wg:s9rt9) 1lpcr+.mxafnb e v 4idkh(?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg8 nh)li47ni;v hl2szwaas9s * 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 balael( rmnmnl y l1-i36a9c (5ibloon, which makes it less dense than the air outside. Suppose the vonlr (cmy elami53 -n6 liba(19lume 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 ai ,,hw(mijt0ktaqh d98 r 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 nymc kzq77y:f.no p8 0k)b:f1 tr4sjfat 18.0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand at sea level ao*6g;9r bwxc+i zs k1tshhpc4ygs q m+2.a(7snd 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;;:x0 ejrcgp9vq6e wd / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many moleculena4oyb(d+ if 9s?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (rs ka 89p-k-zi*s l0rba) 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 volume 5x41: bm7 pm+5 heumzs+ap1+yxiq sc.k.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.cpa 2w7 s 6hk1odl8m4z0-L breath you inhale that were also in the last bresc74pk2 ml1whdo6z8aath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translationa-h d7vw7 8mqnal kinetic energy of an oxygen molecule at STPqn77dvm8-w ha ?    $ \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 o + yyhk/a7i v56xdk0nwfj .rc9f the Sun at a temperatureia f w+9xkc57jn rh6v.dyyk 0/ of about 6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if the temperatu v*qn xltv6+v(ssczn+ nrt9*0re is increa9v*+c qv 6svsrt0xnlt*n(z+n sed 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, given in units of km/s: 6, 2, 4, 6,yydwjgl 4u,m8+een:6 qj0qn 2 0, 4, 1, 8, 5, 3, 7, and 8. Calculate the rms spee6n2yyj+u jewn le04,q8qgm d:d. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas atw2;.a utaokbj/n3w.v;q bvjs/cs 7z1 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 volu,l8o jz0sv 2yjwlp 5q5me is held constant, by what factorlsoz l,5q 2085 jywvjp does $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given yrs9(n3vspishm : ;nim qz5 .v*/vy6vby $v_{rms}$ = $\sqrt{3P\\rho}$ 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 hpeg(/*gt8by.ins,k uttoc5ix) / o+yk60 kotheir rms speeds is equal to the inverse ratio of the square rokb/ot+kxpyg(e ).g0co, ih t k65uinsto8/ y*ots of their molecular masses.

  What is the rms speed of nitrogen molecules contain(sd 4n,0tsin7dzi;whc7kn v* ed 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 mo7w - a7dwqn7p6gtvgx*lecule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance b0b8cg6 8 cku9borj;f,pv b 2nwetween nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecul96 v,rujpz c 3j23.gqj viemo3ar mass is 89 u in a livijm 63e2v3jovzucgj3p 9,.rq ing cell at 37 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a gas can (ir. //pl l s.jpusp6lbe 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 uraniz a;-zm,c9n 30 u cqiefvk4.zcum, $^{235}$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 can 7 ozt 0jn(6e 6ohngj3cqrh4d -fw2m*l $CO_2$ 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 wvdvva4lfo:-,sg9 xm5 7tvx;e hen the pressure is 0.01 atm and the temperature is (a) 9 5a7o e gsxv9tm,:vdx4v-l;vf0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point33 df0ytmbkze ls)vu /)nvo. ( (approximately) if the humidity is 50% on a day when the temperatndm/vu fleyt(03)s k)bo.v3zure is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where wat7q w9gipc6t; ver boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountaintj- 8c.o l/* vreqcsf*s is 0.72 atm, estimate the tempecjr*l/o ce.s fv-tq8*rature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 4zj6ehg 1p- /dvu )qst530 Pa and thee)vs4qph6 tudg-1z/ j relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of waxth5 l(vx/3gmter on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cookeovms1k5c h ;s,* ahza8r if the water is boiling at a temperatzv k5,1mchh s*a8o;as ure of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a r 6+:e spmmq2fcoom of volume 680$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dewzwbzb jo )j(oagb1;*) iic;,j 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(w 9 1l*y 83axnebfqkz Table 13–4) to diffuse a dis3e* x(z n8qbf9l kw1yatance 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 ins 4s4qjk*p6 qmkects to the interior through tiny tubes called tracjkq p6q m4s4*kheae. 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 been calibrated at yx5 xef1 shar8 l0yp8n;z:/ zl20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape measure has been calibr:9unnqob bc51ated 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 cali/x6degzk*9mb4 jyj r8brated 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 aze4*jbj k8/9gxdm6yr re 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 initiall4lf7 5k .pvluex)h0p6 mb1nbpy 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the cyvlb5 upn7 4 f06kxpplh).be1m linder?   

  Estimate the number of air molecules ptqt( + )w;c(l6bnxkk in a room of length 6.5 m, width 3.1 m, and height t6ntqkb cxk );+((wlp2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about o.c,pfugarm5zjr;) pf6dm((h u /x rh;ne 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 usi,i6(p6 xinncxng the best available vacuum techniques is abouncx6i6,in x (pt $10^{-12} N/m^2$ 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 ldpm 5r)q 6ygy1ungs to full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he quickly roser1y5dq pm g6y) to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphem s i6:8z ./nmg*qj)8xvuunara kes8, zx1 uf;re 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 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 re;g/1rf )zx.vnq6* zm8 eu8kxam i:,j sauun s8entry.)    K

  The temperature of an ideal gas is incrk-5p**m4xo2 fmx azureased 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 jqk9 0qo1yxk*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 atmosphek f-78cjy s6hdric pressure at the surface of the Earth, estimate the total hs-ckd8yj 67 fnumber of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules containut vel1w7 d0 d15raq;+k hh0x6ui*rs hed 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 = 2000 p754oupasl/rqpq0y-h7 gisp8+ l ju2qsi (13,800 kPa) and at T = 259K How long will the cylinder la8auupqo4 g7prspql j li5/s-y 2q+ h07st 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 mercury kd s(t ra3 ctrj1g4s4 1 );3,aeyyztocat 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 gasolinhfzj*7/fiao ik(--x ke 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 mwa i6.6 pups0the Earth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto a glass jar at 20 wzcdx 8fy 7 dv:t.3aig,oz),j$^{\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 in the hz(7 caitzfn.9sw,g -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 pr7 92ifa5 yqtfjbd/kcda/v2r+essure of 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from the Earth isk-tgd 6j+qq ptk6x96t $ 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 gxn 7(19vvx1szd.z bav ravity by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg an.vnd1 1za vvxsx97b z(d are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bu np2l.da1nbq8bble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when ndb nqap2.1l 8it reaches the surface?    cm

  Calculate the total water vapor pres0 ufah)w0f o2 :)okbwzsure in the air on the following two days: w ozb:2o 0hf)fwk)0u a
(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 th) 0vogfwizr58g z 1)1nty2whvmo 9-dwe density of iron at STP, and when it is a solid deep in the Earth wvf2i811)5 oy90w rzhwn wmt o)-gdz vghere 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 ideal gas at constant prea3765 idj (v3nplse xdssure, the coefficiep6l(s j i7v3da5xd3nent of volume expansion is equal to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.

  In humid climates, people constantly dehumidify their cella6 v 5v6ur s5sd,qz8egurs to prevent rot and ,6rqd5zeu 8v6 ss v5gumildew. 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