Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodif *f5oeo6nmt0h) +ts rc table or fo omn 0s+tert* )5h6fAppendix B.

Name several properties of m 0n6lg2.jkvapaterials that could be exploited to make a thermometer kg0.j6a 2pnlv.

Which is larger, 1 Cu 8owk/l/zo c1 $^{\circ} $ or 1 F $^{\circ} $?

If system A is in th pyr)o j*uq)lwb/lr 33dj) /geermal equilibrium with system B, but B is not in thermal equilibrium with system C, what can you say about the temperatu */)e)d3 bj3)q/ rjowr uylpglres of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a st7l ypj 4(iiv: t5k3lnrrip of iron. When heated, the strip will bend. Which metal will be on the outside of the yi4lk:i7lpnj5r vt 3(curve? [Hint: See Table 13–1.] Why?

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

The units for the coefficient of linear expansiozn/wvz )/l-aon $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple thermostat+*whl c9bao p9 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 hcw 9al*pob+9is 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 fixed at the ends often have a section in the sb5t c6x4 twle 9qzl c41edhe*0hape of a U. Wq 4w6cbhz1lle x 0tt4 d9ec5*ehy?

A flat, uniform cylinder of lea5c1 1k ymizni/oxi ysjh)741 qd 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 first placed in a hot tub of watek+i7oc u xrjc(+xe p(6r, the mercury initix+6c( o (cpkir7+ euxjally descends a bit and then rises. Explain.

A glass container may break if one part of it is heated or cooled more rapidly tr5hryn bbt.5;han adjacen55y;rbh .rnt bt parts. Explain.

The principal virtue of Pyrex g2da .aliy8ei2u-r t o79q;pts lass is that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Expla2 aeridt8oqp-2. iula97 yst;in why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clocos -auhv 0dr+gcl 3oe4q1i:9/r e77s w lagv*xk, 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 the can + )jpna cqms-3will not stand up. What mn q sc3j-a+)phas happened?

When a gas is rapidly compressed (say, by pushing kymtgb/6 /7 yet:avy72xv; s jdown a piston), its temperature increase:27 etgv;/st yk6jyxb vay /m7s. 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 when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged in water increase or dg3ly y ziqe;**uq,o+a *wk h9tecrease if the temperature is increased *oyqq3 z*, yt;kie+*auh gl9w from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and thpj: agw 8dh3tpwc8,0x e relation between aver8pxpwca,td h : 8g3jw0age kinetic energy and the absolute temperature.

Explain in words how Gay-Lusszdwv0i qx+ekb5lf r; 52jx8x/ac’s law follows from kinetic theory.

As you go higher in the Earth’s atmosphere, the ratio : sez p2qc7w)pof $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speedzm:hqu( 5y jfw21 yq.z an object must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what iz2h :yqf1z( ywmj q.u5t is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more q)or zr2m):4gr1w gf wtuickly than water at room temperature. What can you infer about the molecular properr)gmt1w) f r2 ogw:zr4ties of one relative to the other?

Explain why a hot humid day is farr; b gec 6b;wl(h0r,uio*wj7u more uncomfortable than a hot dry day at the same temperaturoebwb*l0;;cr ,i6( 7rugwu jhe.

Is it possible to boil water atxnhpcg s 33tti4w p(+ q+gy3c- room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the hl p jf5/p9gre,umidity is different. Which is more dense, the dry air or the humid air at t,jl5 f9pprge/he same T? Explain.

Explain why it is dangerous to open the radiator cap of p+-mf5 q-ts q-piqd,jf lzb,5 an overheated automobile engine5-zq - t qf,blqpijfp+-5,sd m.

Why does exhaled air akcd (t(s;t )ugppear as a little white cloud in the winter (Fig. 13–28)?

  How many atoms are thezga vnwpbg1w)x)st 5 8zi) +s,re in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-ue-0(ipwov w)gram gold ring compare to the number in a silver ring of the same- )( 0wuiwevpo mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. Wha ,6w:lzu2tlien+,yt ut is this on the Celsius scale?: ylzu 2nwl6e,itu,t +   $^{\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 vzojw. -ar2n 5g ud75jlowest temperatures recorded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

  (a) 15 $^{\circ} $ below zero on the Celsius scale is what Fahrenheit temperature?    $^{\circ} $ F
(b) 15 $^{\circ} $ below zero on the Fahrenheit scale is what Celsius temperature?   $^{\circ} $ C

  In an alcohol-in-glass thermometer, the alcohol colygifdq;s2yv u9vm:k km6j-.4,2pys m umn has length 11.82 cm at 0.m :g2;ym4,-2.6kf ys dusvyvqpkm 9ij 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 5l 2xmp;9rq(pgwc u(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) rc6+rv3ivjq rz0e 2mfdb 68 g0is built of wrought iron approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and Janjic+ f6 qr20b g3vm8d ev6z0rruary (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 tq8z: pkf.fl0ihan the rivet hole are often used and the rivet ipf iqz.08:flks cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter at 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water *xy lgh;f b-;,ri8 , jf3c:7aoujljx24pfgnlat 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 xb; bxr 2a(+i.8krx. bglsu)f its change in volume if it is ;( )xb+g8 f.rxibkul.rsb2ax heated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL of water at 100.0 vq+2)pnl * ji5j5ee4h)-zn kexaww/r $^{\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.*qkhm +5tr3 urrb*g t350 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 iron. At 20j3/2kn,kx* pct;fq g *obd t(g $^{\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 essenti z *44j 5fpjjes5:tiiaally one direction only, show that tij5if4saj5p4*j t z:e he effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change inp 3t1rex9 we;x 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( ;)lbw /x2putb :mkzw of length l and width w has coefficient of linear expanz :wk)mbp lwb;u 2(/xtsion $\alpha$ 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 isotronn kgtl;iu,8ifoh: eh6w i3:7pic 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 grandfa ivli sk+ zsu(e(m*:y8ther clock is made of brass and keeps perfect time at 178kz(i+mvs:se i *l y(u $^{\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. Thy 0/ a6hygh8u 20tlexke bulb has a vx28khh 6tyl0yeg/ua 0olume 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 cylindrbya/.ihu( nt jlzsa1kl +yo f5i*8/z9hsk07wical wheel of radius 0.41 m is rotating about its axle on frictionless bearings wiahj 1/y50s/s nafzl t9uo+ .8iz ik7(l b*wyhkth 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 stress is requirii;b*ur1neoax g; 6 -qed to keep it at this lengthi6 xr1b;a-qou;ngie * if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-0)ctyjof/ j: p: l)afpbeam of cross-sectional area 0.041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 134.122tnmt k.v -l,z+ 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 Kelvi)e-df-6b rhlgcw cm6cp 4,il5n scale:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temp8f 0ejcjfp1c bw 0if.;erature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior v,7gonsh89errzvn.5 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 pj fnd8bt0v :5jp( t3txressure and a temperature of(5bttj j tnfvxd:p03 8 about 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 densitegp8mk;jf,cbs-.o ryz9h5g )y of oxygen at STP using the ideal gas law.    kg/$m^3$

  A storage tank containw3gty52 weh2zltk(agf a rusq:80 (r*s 21.6 kg of nitrogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.5 kg of ao - lyf,e7yw6 /(cezqnitrogen ($N_2$)
(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 10ob l2mka4z wy6ul(1ix6p. rku at5 2)a.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside a 35.0-L contqy 9y*slfy s09)2bl:wx bi6urainer holding 105.0 kg of argon gas at 385 y0 bui26f:r)xqlys* bl9y 9 swK?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg n0r(m-l( at swof $O_2$ 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 the65scg mol ,d.3e uu4l 7xlavk9 air inside the balloon, which makes it less dense than the air outside. Suppose thx v.6e,au7l4k9mdocgl3 l5s u e volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air at 15 tmo68+eg5 k uo03h1lv9erw7ugpq,y m $^{\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 18bk e37lvmzj83 .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 levelxzz*8t5yn o-q 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 molecubxf)k ,t i0,xhles / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in hy-pmudy 6i:ul ivi6 c/b2./s1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number otti3ew*2q-6kpzlikhxcs g :yeix/vc. 8 d/4 )f (a) moles,    $ \times10^{22 }$ moles and (b) molecules of water in all the Earth’s oceans. Assume water covers 75% of the Earth to an average depth of 3 km. $\approx$    $ \times10^{46 }$ molecules

  A cubic box of volume y x 7-qhpw)7e phj 0( cw03ppzd0c:mvp5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L breath you inhale tha5igplx piq9357 m 3e.ewu/vsk t were also in the last breath Galileo took. [Hint: Assume th95uivs73ep lew m5pi3 /.gqkxe atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average trqq;lhy .w:x f(anslational kinetic energy of an oxygen molecule at STPlxw; (qq:y f.h?    $ \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 on*) 3c0jq bv9tsie oc4f the Sun at a temperature of3s vce)n9o q0jt*4cib about 6000 K.    m/s

  By what factor will thw; eq mdzijaf6p42 i8;e rms speed of gas molecules increase if the temperature is i ezwad2m6j fpii;q; 48ncreased 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, give-r4kb9el u3v /vsy+b en in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and9yree-b bsukvv l/4+3 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of moleduz 90 4wfzk kizato 73l4m21ncules 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 volumr9 9 b po.2rgc qzy:y.hg2;lxke is held constant, by what factor does k9 b2o 9:ch2gqg.p;r.rlyz yx$v_{rms}$ change?   

Show that the rms speed of molecules in a gas is gnl;xcpugdvd bm b.+::) -u4ukiven 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 team69q:i ouetkuaog,i:43 tahp+(l xit(q 5 q)mperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of thq 3p5e itaq,4ii ah9 a )(gxq:6 uloou:(t+tmkeir molecular masses.

  What is the rms speedm (xkqav2z.nm-5y0kp-r2 gtc 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 rm dq(g2 hq.bgd2 nhn06ps speed 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 distancezz 5,qolixfwa - o5)d/ between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 utln7odl* 7t 8dw)0 hds in a living celdl)on 7 dsl7hw td0t*8l 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 be w1e sh5)m: bcnkritten 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 uranium, -u-ut dqo568l +f 7zc.ssjgut$^{235}$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 phasesc;l z0*ll . i6vybriq* 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 tz:p:pabvai5yb3 v: /z he pressure is 0.01 atm and the temperature is (a) 95 yi v3v:/:pab:pazzb0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50%ep2-6u2gz j ku on a day when the temperature is-z 62 jue2pkgu 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a pla;.1*e mqq c0pelpyi2kce where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a byzw;h )a,pdc8wk(gr ;m 8h-k particular place in the mountains is 0.72 atm, estimate the tem,8-wm hh8by ;)ak grzd(cpw;k perature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 530 Pa4z fk2k .kns/g and the relative humidity is 40k gszk42.nkf/ %? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the temper uz 0yac;vc028w;1 p1 el*tiwsevu)teature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressureos0c(wg a 96hv cooker if the water is boiling a9h0vwo sa (6cgt 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 of volumozh-s7 -gba,bige +p+e 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 den-4kfo-vmk;wq8 nc tq94bv b3w 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 gkk/x67kjk co ig4otf09jfp(uk/ra : +lycine molecule (see Table 13–4) to diffuse a distance o: k6j/kxfkj ruki7 t g(a0c /of+94pkof 15 $\mu m$ in water at 20$^{\circ} $ C if its concentration varies over that distance from 1 mol/$m^3$ to 0.4 mol/$m^3$ Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u. t $\approx$    s ([color=rgba(0, 0, 0, 0.85)]Round to one decimal places) $v_{diffuse}$    $ \times10^{ -5}$ m/s
$v_{rms}$    m/s

  Oxygen diffuses from the surface of insects to the interio1rdov;h. ( tq u5 6fzkk1mof3wr through tiny tubes called tracheae. An average trachkro 31zho m6w.kf ;(5tvudqf1ea 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 20s(c z.;jvm j0v eo95ap8xwgv0$^{\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 calibrh,ooo7 z. c9qiated 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. How much er)+.qg-(gqi uyr(rc cu)h4yh hror will be made in a recipe calling forycr))h -q4(ur(gg hcu+ yi.qh 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 helium gas cylindoph 7a x+j9ep;er is initially 28 atm. After many ballap+jheo x9 7p;oons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of lengguc;69epb(:y-t -wbwa t5u-xwh-wdq th 6.5 m, width 3.1 m, and height 2.5 m. Assume the temper ut- bt ucw9- w 6a-p-g(qwyxdwh;be5:ature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter i*9ezh5jj o1 lfs about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable ux+w ji+djdi9 5sing the best available vacuum techniques is abo xj+9d+ijiwd5ut $10^{-12} N/m^2$ 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 i/nqvi :60zhd L when 10 m below the surf hivqzi:d60n /ace, to what volume would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters+si 1dmxr os(i5ema7- Earth’s atmosphere 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 smaxi(e1 -5omr7ssd+i een as a bright blaze upon reentry.)    K

  The temperature of an idf3cfemau1, *k eal 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 7707lhjzrg;1bxd(9rmn +yf( i 6um$^2$ (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 the Earth, esvv oif-k: 8*so35+fldeir6e dtimate the tvoe*v-i8 seko+6i:d flf53drotal number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen a y,:pr kouo8-molecules contained in a 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygen used in a hospital has gauge pressure = 2000: 0mvmi8)ut1llcv uz*unks5 8 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow ratevc ivz n*utu81m):k0u85l lms , measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liq eqot04qt ) nbid/t25suid 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 at 038zzt/w k ob*ykesh1 0$^{\circ} $C is 0.68$ \times10^{3 }kg/m^3$ What is the density on a hot day, when the temperature is 38$^{\circ} $C?    kg/$m^3$
What is the percentage change?    %

  If a steel band were to fit snugly around the Earth’s equator at 25ock3ljn. t24 c$^{\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 glturugw)j l4l *(4 sai1ass 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, adopted qa4qg7 md-l;is,pzv 1 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 atm at 20w:f( cijjl4 ll5kr fit,.de9/$^{\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 ths9)o c)oob(ple 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 agaiigg2*:x wy6sa7s fgjv 60fa3 tnst gravity 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 0.0x7aw yfgi2sg f* v63t0:6sagj 60 kg and are thrown at 12m/s   balls/s

  A scuba diver releas k ;;-yhh lpnoeso338kes a 3.00-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it reaches the surf o3-;;yl8ehp3nhk skoace?    cm

  Calculate the total water vapor pressure in thkg s6;.ia)7 ptw24y mc.f h(gm xnwoe5e air on the following two days: mf25wc 4spi6;). .7ankxyhtw g(meog
(a) a hot summer day, with the temperature 30$^{\circ} $C and the relative humidity at 40%;    Pa
(b) a cold winter day, with the temperature 5$^{\circ} $C and the relative humidity at 80%.    Pa

  A sauna has 7$m^3$ of air volume, and the temperature is 90$^{\circ} $C. The air is perfectly dry. How much water (in kg) should be evaporated if we want to increase the relative humidity from 0% to 10%? (See Table 13–3.)    kg

  Estimate the percent difference in the density of iron at STP, and when it is txq/xtccv 0)a6(/r bda solid deep in the Earth whc6a 0(/bdr)v t/txqx cere 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 toh:8)ddt8s*1m0 go fxd 3cbbn/ sza g7 mv)slf2 show that, for an ideal gas at constant pressure, the coefficient of volume expansion is equal t7/s3as cgfb f*thdzmdmd)ng18:v oxlbs8 20 )o $\beta$ = 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 the) *9.nhr ddjc*p* (- ffzdthk w7hha4oir cellars to prevent rot and mildew. If thejk)nhrd4wf9h( z p t. -*7dhod*f cha* 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