Which has more atoms: 1 kg of iron or 1 kg of alzdp /.ifxg;j..xkib /uminum? See the periodic table or Ai/.dkf bij..xgxp z; /ppendix B.

Name several properties of materials that could be exploited to6j8l y ew3a-vyuf.)d xvvb:h : make a thermometeh wyejlvd:yx8u-bafv. 6v3): r.

Which is larger, 1 Ce6 d 1 pkwpv8b1pwf7l9 $^{\circ} $ or 1 F $^{\circ} $?

If system A is in therma0p zfyea92w 1ml equilibrium with system B, but B is not in thermal equilm1pzfw0a2y e9 ibrium with system C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a stripue)f4oquj7as5 - 9 pft68tuwqa (n ,sx of iron. When heated, the strip will bend. Wh78t nf oj9usqsqufa-(pxa5 w,t6 4eu) ich metal will be on the outside of the curve? [Hint: See Table 13–1.] Why?

In the relation $\Delta$L = $\alpha$ $L_0$ $\Delta$T, should $L_0$ be the initial length, the final length, or does it matter? Explain.

The units for the coefficx,g1qhc ms+zyvvds8 3)+ 1wd5)r ybgnient of 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 simpc,ucjk 0 nli3tmg9:(nle 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 c ij( kcn3u nl0gm:9,thow it can be set at different temperatures.

Long steam pipes that are fixed at the ends often havc ; ; 0s-ptnd(2yt2d dq /dds3es.gn:odv3zyx e a section in the shape of a Ut dn3ycd0 3-g d;t2qyvdndsops.zs(ed/x; : 2. Why?

A flat, uniform cylip b/2k,x-pcc5o.w bb ujr(z56r +h-pi rbvx b2nder 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 thermometer is firs-scd -35u.h)jx1i7qyq atv-q 5i1h c uqt)t zzt placed in a hot tub of water, the mercury initially descends a bit and then risesi1 qjhv s)-i )1tdzh.u3q-axztqucq5 ct-75 y. Explain.

A glass container may bre( tlkd)l.;rhd +n-xhhak if one part of it is heated or cooled more rapidly than adjacenhtk dlr ;+l-.(hnh )xdt parts. Explain.

The principal virtue of Pyrex glaspd /r krr0us ,sx)ph*2s is that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why t pdprs*x,usr)rk 2h0/ his gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, y;.:habsn* jzvop0+h accurate at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and top to bulge so badly twwgb(g/00qlmw3ay jl 2n7l,f ;im a /khe can will not stand up. What has happe n/bl,2 0jaif(gw3y /7alm;g0mk l wqwned?

When a gas is rapidly compressed (say, by pe:c xun k(dmx+7,vl:uushing down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in tempe d7 u(::+v,xlcekux nmrature 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 or dec vd+ ;wmz ,:f*7xgxbqg 0obvg,4sz h9vr2w)hhreas4gb:0qv hs;,mo9v h)xx,z2r7g+zhgvwwb*d f e if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic hqk+vjco +v wrzyv7v:/,wh4if ,mz) ;theory and the relation between average kinetic energy and the absolute temperature4 7 v;j, v ,z:vv)cmzh y+k+ofwh/wirq.

Explain in words howrh;,ga2 fg8f d Gay-Lussac’s law follows from kinetic theory.

As you go higher in the Earth’s atmosphere, the ra 6lz qi7q.r *nh0v1cb2ra28h r7bos bdtio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for t o3/g t*dwt3zthe Earth refers 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 what it is for the Earth due to the Moon’s smaller mass. Ex t3zgo3wdtt* /plain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What can yq(gqrvb nkf1 n6i+99nou infer about the molecuq (ni99kq fvng1 6+nrblar properties of one relative to the other?

Explain why a hot humid day is far more unco2o.m8 .(wnf vfvplx4v t /a6skmfortable than a hot dry day at the same temperat.ms6f k4w/ vp(8 tfonv.alx2vure.

Is it possible to boil water vrjhr0a- 6 tr:at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature isnyr7l3u3c3/5 v fwokw the same but the humidity is different. Which is more dense, the dry air or the humid ai5/ wwk3n yru3 ocf37lvr at the same T? Explain.

Explain why it is dangerous to open the radiator cajpma3lcz+x;a s(r 45 tp of an overheated automobile5zxc(mrtl + ;4jp as3a engine.

Why does exhaled air appear as a little white)kxdf h,k)pn .) koh1a cloud in the winter (Fig. 13–28)?

  How many atoms are there in a4sy/1kd( we wxsdam g3z+u ,:a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the number int:mfnljn oc1 /a1si /+ a silver ring of the same manm/t :a1 jf/io ln1s+css?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the C a61zl*7,khmsiudleq wr.evw j.5 +2 zelsius scale?2 h+l5mk .djierv qu6zaes.,17wz *l w   $^{\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 recordedxtnpqp0w8d * 3 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 length 11.82 cm aa ojlhf0p hs. q:/lba-8oj8x* t 0.0 ps:0jo/ql l a-*hah8j oxb8.f $^{\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 )ou 3m;ka f-ce7txx9 rslabs 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 (Figarz m0 y69ab j(9nw-.texwf v*. 13–29) is built of wrought iron approximately 300 m tall. Estimate how99tfn* 6 zwx ayr-ebjmaw (v0. much its height changes between July (average temperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, rivets that are larger than the rivetuc) qmxur2 cq 1es*/,px0 a)5saj/js o 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 to be placed in a hole 1.869 xu /a0 s5/,axq12c esjq*rs uc)jom) pcm 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 a :owxpwrr shee1 r msa6 k,(*5xhy888yt 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 diairvrykx:n m82 ,6vq5qmeter. What will be its change in volume if it is heated from5 vx8:k miyvn2rqqr ,6 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brncl8lga iyr7. c1i5:y im 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 5g( ))io tdin1fgbd6,a 5.50 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 made of iroe( g ihx9c4i hqbcir6 1kyy4-8n. 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*qxjbq4/c1m8 rutd6zje ik 27 so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximately eqj qd274mq u k61cbrzeij*8/t xual to the coefficient of volume expansion $\beta$.

(a) Show that the changei 00th avm iv6ai )6v*dwq5 .c0y:cu5swnj6rz in the density $\rho$ of a substance, when the temperature changes by $\Delta$T is given by $\rho$ = -$\beta$$\rho$$\Delta$T
(b) What is the fractional change in density of a lead sphere whose temperature decreases from 25 $^{\circ} $ C to -40 $^{\circ} $ C？

A uniform rectangular plate of length l and width w has coefficient of linear2+aqzzi+v p/qyx 2g8 ,/ukxe g expavx8y z2+/ pz/iaguxq+e g,q2 knsion $\alpha$ 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 sdw (bgho90rj .olid, $\beta$ = 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 clockr2m6*n7xva ya is made of brass and keeps perfect time at 17ayar 6mx *n72v $^{\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 b, :n5z /* mrl,iogkrylulb has a r5/*zyin orl,,lgm :k 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 radius 0.41 m is rotatinrv o( t )rt*g.v7jxi,dg about its axle on frictionless bearings withvorvgt(7id) x.r t*,j 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.98gv 0dyr4vww-;meo v How much stress is required to keep it at this length if the temperature increases to 35wom0vgy89vd;4-ewv r $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional arzc5 8spv6hh 2fl7 po3aea 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 diametersj9jsv0qe1 *u 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 Kelvin scale: it3) 1m/ ho:zce5k/nw:r vuag0z e9hy s*e-jk
(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 j0 e1zyvk)wk;*hsfz.z 6 eg,x on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the 5mxkyz twz vb(5r5f (.interior of the Earth and Sun are about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

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

  In an internal combustion engine, air at atmospheric pressure and a temperatu-al)m h ;reui8pz u :5jhl xu2hw53tz+re of abol txam5u5whzu)8 +h:;jlh3i2r z-ep uut 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 g2i8 y w6nc 4,and-yzzras law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitrwe97(xm *uz**valmqh ogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.5 kg of nitroge2ch77p w-xn5 o0su j7d5erb cxn ($N_2$)
(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 heliumpho49b(gytlsglf 2+ *hf6z q4 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 a 35.0-Ldv a6y,q4kh( d q/(vs8naruwmj:y :y7 container holding 105.0 kg of argon gas at 6ynkh q :u/q4(y(rsdwm vaj 78d,ay :v385 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg ofiwdzv(ga6j + ri.8qy6gc 7i1f0kt / pd $O_2$ 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-d 93+w31*sydaie lo,roou+wma:m ed air inside the balloon, which makes it less dense tlrdsi mmy9 aee+-+a,w 3*u odo 3do:w1han 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 airyo. y . xe0)c-ilb*ssc at 15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at 1csw0j(a 2c c kip3xl3k 1n4,xh8.0 $^{\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 20.a088yjmfi+j7+ xeae. ; e)yjjxwl1pv0 $^{\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 numberewg( f 8gqh)h7kz3q,p of molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are aggd7f07e9olt e vfit/-u u2 .there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) molesk uj:6qftdpdh+xt-5 ),    $ \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 eo )-spw -0r ps-- +l(:fsmp,wwaycwn 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 jkt;xdk5j ,h 1are in each 2.0-L breath you inhale that were also in the last breath Gal;j 5,dt kjx1hkileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average bc t3(l .dx1do*/lsnb translational kinetic energy of an oxygen molecule at STPd3 c lsxb.(ndbo1l/*t?    $ \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 .o piwjqp+k6)j z( l8ra temperature 8p)(jkrlowp j iq .6z+of about 6000 K.    m/s

  By what factor will the rms speed of gas mo1n9xag7c9mafp c fs .1lecules increase if the temperature is increased from1apsf .mxa97gn9 fcc1 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:dowfrz(cr,l g f2l -cye7rfgp 2:.*z km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate the rms speed. fzogrfd:(c:gl*r r-z f ,27ecy 2. lwp$v_{rms}$ =    km/s

  The rms speed of molecn z2;yfsqb qg*u r8tt ,:8i8ihules 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 const qx)tuls5-hq2t srmr v1+r8 1nant, by what fahsrvt )tr2-1q5 xsq rn +mu1l8ctor does $v_{rms}$ change?   

Show that the rms speed of molecules in a gycxe)w8 196r c agd5ldm-g(puas is given by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two gases at the same temped+o z2ol ,im-,pg:unpg n )g;trature, the ratio of their rms speeds is dp ngopmo)lut,+g,z;g 2:n-i equal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules s- /zi/ 0 a.lgi uuumylc(a)a)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 e44 fshgj7 ; fi5mdz5jspeed 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 distance between nitrogen molecules ar+/unte1/ s ll zgnqd) yv0g591dy( cjt STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino ath) y2 bhdi9h9cid whose molecular mass is 89 u in a liviy9 b2h9h) hitdng 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 pressurea0mrgm3s43ik P of a gas can be written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uran)o :t,xebgctc-m3g w66 /ulm xzsn2y(ium, $^{235}$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 c:g. 0 o axbyx)rvqp8e+an $CO_2$ 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 is-l +4:d/4ma(dzhtbu gyri lm/ (a) 90 m:(d/+d y/4 lt4mbu azhi gl-r$^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a datia 9mffzxa1m;lm(2a.ln s0( y when the tempert .fi((a a1mm mn9l2xz s0a;lfature is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a plxngt h1w4 yu.+ace where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place wl + t g.w-9a0u6 xlwdy;,wgbuin the mountains is 0.72 atm, estimate the temgalg b wtdxw+;uw-0,w ly.96uperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 530 z lth70nfj wvid n02/)Pa and the relative humidi lh7 w0d2i fjn/z)ntv0ty is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the temperaturr0:2y03:gy oo s9wr.if fr5qk nflwo:e is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate 14o5z1zhceyz pressure inside a pressure cooker if the water is boiling ah4zyz5 1ez 1oct a temperature 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 /e 0y56xjbe vrof 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 point0)) apc+ xgyhdx;fl f4 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 glnuihow(/ .7o g03 9 yryce-kheycine molecule (see Table 13–4) to diffuse a distancc y3h7/i(-.n9 e0rueo hgykwoe 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 sur4fmh5p *dxme +3 n 8kru 6pe87kzlirg.face of insects to the interior through tiny tubes called tracheae. An average trachea is abpprhe+n88 . i ge rufld734*mkxk6mz5out 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 mepll-93b7e c osasure 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 precise steel tape measure has been calibratedgob0lm , h;e/5m0sqjw at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room temperature. Howox1o h5q d u::isd.2uoo7xf/w much error will be made in a recipe calling forwoo/ fddui:u x:hox 12qo7.5s 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 or2 , x *glne9jxt3kc,helium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atexcn o*,3k 9tjlg2r, xm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air mol5 hxktn .k-rkci2a 56gecules in a room of length 6.5 m, width 3.1 m, and height 2.5 m. Assume the temperature ih5tan-r2 56k.ki gkcx s 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is abequm7afw+p479sy+ f bout one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best ava sxaqv /-j/q*sdj)e 2nilable vacuum techniques is aboujq*qn)dse-j/ 2/ vs axt $10^{-12} N/m^2$ 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 below the sk 85p5i ) w4dcjqecp0purface, to what volume would his lungs expand if he qucew q5cpjp4i) 50pk 8dickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphereeb+dwwx6h n 7),f6kxt 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 kb7wxw e)t+6x 6f ,ndhdoes vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an idelm:xn7s8 -p0iiucy )g al 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 77 .ek(8ff4y gxf0m$^2$ (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 surgu id54u-d) gyface of the Earth, estimate the total gg u4d) -id5yunumber of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitroed3x x5en 5pc9e waj;6gen 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 gau)ovm8isd; zu+e+ oip1g7s (tege pressure = 2000 psi (13,800 kPa) and at T = 259K How loe z+usdevpsoii 7mg+(8;1t)ong will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats l9f i2g2 ,4 qslhp-w-sozgy4hin a bowl of liquid mercury at 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasoline 4pahjx9t;)ua vo *jk8l1j vboh mt/65at 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 wereckjr fh av3**0 ,r0lro;ecl6b to fit snugly around the Earth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto a glass jar at 27 r95d to qku,znr2nkb-h3 i.n0$^{\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 18v(p7xoc90 mjw d7zw8b$^{th}$ 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 pres2gwydxt s / ,z03(l;u;peyb zpsure 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 Eanqvj /3ag- h5mmcu6;trth 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 gra4 stg w:j*mxx,jb;l/f puw+5 uvity by tennis balls thrown vertically upwards/x5u ljm,uf*wt+pg: ;x jwb 4 at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.0fx w vku-wo*: n6u,ti052xpe9kof/ eq,sxvi )0-cm-diameter (spherical) bubble of air from a depth of 14f0kf )/xwou2 u*wes: peonvvt96 q ik-,,x5ix .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?    cm

  Calculate the total water vapor pressure inh p 6 uv+3+fn7vfr wcm8y4n/xt the air on the following two days: uv7 f+38xwt4 m+r6cn/fvhp yn
(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 dif c8o maob(u8+syw0rg -ference in the density of iron at STP, and when it is a solid deep io y(w m0 gsor-88+cbuan 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 gas law to show that, for an ideal gas at constant pres djv 6hs8li00/o4 :7tgjulpjx sure, the cojtlvhjp/i 4008og7x : dlj s6uefficient 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 cellars to -e/.b lri*w(oq/yuy hf 8bh24r4id p bprevent rot and mildew. If the cellar in a house (kept at 20pq(*r fw bb./ oh4-l4/yhuir8byie d2$^{\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