Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic 3 y bhy2re*sym5y7ii9 table or Appeny257e*myi3i 9 srhyyb dix B.

Name several properties of materials t9*;v zwu 5edujhat could be exploited to make a thermometjv59 ue*wu;d zer.

Which is larger, 1 C j8v(rraf hek.17 eg+j $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium sk54+c9 s;fdwgvmbw * with system B, but B is not in thermal equilibrium with system C, what can you sa* ds94w;mk b5wgv sc+fy about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted tkok7;cw,: nd whv+ cy*f5bee5 o a strip of iron. When heated, fcvk ney,we:b5*+5 wd7 coh;kthe strip will bend. Which 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 coefficient of li6gyk(zv.9anu41o)b-/jjz t b e 6axv8wa8 ulhnear 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 simple thermostat used to control a fdmt)y ;;-niuf urnace (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 de-dn f;yim);t uvice 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 7trs7+v i2j3datej) :hq 6tlrthe shape of a U. Wit: 7s+dta 6 j)3jvlqr2 te7rhhy?

A flat, uniform cylinde3 eg h1owdq 87f)avi9er 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 first placed in a hot tub of c/ . vogk7oj*twater, the mercury initially descends a bit and tg* ok /ctv7j.ohen rises. Explain.

A glass container may break if o nwm,r/j 1p6ip8 e76,cpmraidne part of it is heated or cooled more rapidly than 6j8i/ 1, 7e,mcd6rwmpippran adjacent parts. Explain.

The principal virtue of Py loi44zzm2+o 4e;pf;iy 6m zsglw*n ,mrex glass is that its coefficient of linear expansion is much smaller t ozmy2*44l;e;i+fwsz,6 mgm 4li opznhan that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accuratemaem h 9t43o1ydj6nq; 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 ch2 paa 9b1ql1t )ouuea nv(k+6ause its bottom and top to bulge so badly the can will no(uuo1)+akbta9lp6 va 21n hq et stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a p9 th9 xnurk--fyh fa1x96z*zmiston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in partfmx9h9f uhxz*6-9kr1n zta y -icular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged ym7fd1ivzbvwzl73 y+-btv9m v d.6w7in water increase or decrease if the temperature is increasmw-w td7.ifvb m6 9vdl 17zzy7vyb+v3ed from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows fs x ue8z6uyb+2rom kinetic theory and the relation between average kinetic energy and the b u6 +2ez8suyxabsolute temperature.

Explain in words how Gay-Lussac’s law 8*vj tf l:c.;q(8 drwod lpsf7follows from kinetic theory.

As you go higher in the Earthsdr(ot-a 1 88mvqzd5u’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an jzn69b/ lnoe3obi0 c -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 has practicab0i - ozlb/cjn6eno39lly no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What f98 .lz*fb*y8svtxpu z.p(mk can you infer about the molecular properties of one relative to thet .zkbs8* f.m*fyl (pzpu89v x other?

Explain why a hot humid day is far more uncomfortable than a 1t(epkgq d(y c3 ii5(yhot dry day at the same te3(( 5ekgicyip y1tdq(mperature.

Is it possible to boil water at room tempern ly7 9pnsj n xi*;,0aavqw.k4ature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humiditk2; x4wfoo gwj l: qy9d5ob1;ay is different. Which is more dense, the dry air or the humidf9kd1wg oxa y;q 2b4low:;5jo air at the same T? Explain.

Explain why it is dangerous rpt9s-;7h p4rc/lfj a to open the radiator cap of an overheated automobile enginerr7ah9ltfc j s;p/ -p4.

Why does exhaled air appear as a 73ulum(5q k.f+nzezxpvl z6*little white cloud in the winter (Fig. 13–28)?

  How many atoms are there k7*n3tp9 8q0w izpcuh in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gorz)yz;-b gxq 0ld ring compare to the number in a silgbz zrxy0 ;q-)ver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is oftej81blt o4y f0lw x6om8-aevvby7.m k.n taken to be 68°F. What is this on the Celsius scale?beyo wfxy08otb8m jvvlk1.4lma -76 .   $^{\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 recorded are 13ho*k30: hs +qe8 bgjw 5vgvka )vpf1)c6 $^{\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 tha/fymjh4 1m (yermometer, the alcohol column has length 11.82 cm at 0.y/ma1fh4j m y(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 buo. af*u8q e(tpilt of slabs 12 m long (20 $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

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

  The Eiffel Tower (Fig. 13–29) is built of wrought r6(a +pq.vc- no0( ( p-hefnwvlj.sco iron approximately 300 m tall. Estimate how much itsvqopw+o(a (j n .l-cf( rn -0.sce6pvh 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 lae4u4k t*v oei 1je)6htrger than the rivet hole are often used and the rivet is cooled (usually in dry ice) btu4 vk6t*ie)hejo1e 4efore 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 at cten v5/d0)otqg8 r,hkw r/.b 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 8.7x; 5+o3 ,c.(r grovdlh9jsj ydb tm-7w5 cm in diameter. What will be its change in volume if it is heated x+lbsm3 7t 9 j(h,dgv5ycrdrw o.-jo;from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to thetticx15/ ( nxtq4me9y 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 55;+22v 6 ,rrza xreh :lcu9pzfs)j1loa.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 tokcr8+p-1 n,aehgdz z0 be placed in a ring made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, narrow vessel so it can expand in essenro/ pd oo-.6tmtially one direction only, show that the effective coefficient of linear expansion is approximately equal to the coefficient of o.r6do- / pomtvolume expansion $\beta$.

(a) Show that the change in the density(u 74rqrdr xj w(dmu, 098iqst $\rho$ 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 tzurz (h.5t u67u)y eihas coefficient of linear exr65u (u7 zz) y.uttihepansion $\alpha$ 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 s ;rw*lf0h1gkxolid, $\beta$ = 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 perfect geh5 ge5el,b+ 3jq07m0zs ooe/ccp2scxl5 u,time at 1pc5ezbec0 ml 3c j,sehlg u2 sx+og0o/75e,5q7 $^{\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 ofqn mctl) 5d /goou)7ygqw55e, 0.140 mm. The bulb has a volume of)o75 ygogn5u/ml, 5cq) wqd et 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 mv4.cff.oc* nh8(lapm is rotating about its axle on frictionless b4c8 .pa.hfo (l c*nvmfearings 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 a,2 nst7u5, yyd.cys 0 zx8stwpt 15°C. How much stress is required to keep it at this length if the p2tysc.xy d78yzu,st wn0 ,5stemperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-secta rm p )4i /7.d,hi9wa;uhbhtrw(zh p;ional 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 134.122 cm at .k(v,s tgyd98xvl :ngcw.va 420$^{\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 Kelvi7 cgjar; hl18on 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 temperature a oa2/h i:oijs* txtgz804ct-on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the i islla:uz*g-w qzi9e 0 d+vw2+nterior 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 eng:dik0 ki( po wpo(ah;1ine, air at atmospheric pressure and a temperature of abpk ;d:piik(a(w 0 o1hoout 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 ideal0b v,,x*pef+ay7x hr f gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of r3v;7fo zw bq8nitrogen ($N_2$) 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 nitrdp4(n* (.yrtna0q-ai7pbuf hogen ($N_2$)
(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 at6ogde7 nckgbt* u 6y** 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-L container holding 105.nosmitv03q9 )gl( em7 0 kg of argon gas at 385 K?q7mvni30est)9( omgl   $ \times10^{ 8}$Pa

  A tank contains 26.0 kys7mhn z 0*y:rg 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 aim:m.q93pjnj4q c6z+l lfk gy4fln( v;r inside the balloon, which makes it less dense than the air outside. Suppose thv lj(lznn.3 +jqqmlkpmf 496 ; 4fgy:ce 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 p x5dlsss/cq ndw,1saj: m7-8( rp -cv15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at 18.0 ))vh h5*sw)fe6de8c x:na z ao$^{\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 20q1b kb*(rzme. /fym*g .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 m w ypjm.8q *j(zk6gy :ksa3s.oolecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are bu17x :fhsel4j5 tab1r srr+:there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a)2lv h+,r 9lgij 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 b*pr:ge5 akv 55.1$ \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 moleculsk /ubju ahf5691 (fjtm+:ago es of air are in each 2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant/9(kth bujg5 af+m 1a6: sojuf density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen molecule ixd i.zz8l1 g7at STx lzz1 giid87.P?    $ \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 ate w;es8ob 0-qg *tv e-zkoe4(xv+mp:z a temperature oezevbtw: -poq+* ;o8e40 (mexg zkv- sf about 6000 K.    m/s

  By what factor will the rms speed o o2pt (vysauy:3c en90f gas molecules increase if the temperature isu:y 09c 2tp3yoa(vnse increased 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 theq vea1+hz 2o0.emseui; 3jt)b nd1 7st following speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3v bs nee2101q; stzht7 m3)ia+eudj. o, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a2izhk6k hay*rr-i v4t7 cng/8 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 constant,1uq6uhy5/ exk by what facth u/u56exy q1kor does $v_{rms}$ change?   

Show that the rms speed of moleculesu)/ 1gm1w ywyc6, jnwxg5 yn9r;s1e mi in a gas 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 te;ae: z 3 tvo6aecd7z8wo gases at the same temperature, the ratio of their rms speeds is eeaz8;:3da tezc7e o6vqual to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of ndynf)o y4rkw7zqtp64)x a,;vitrogen molecules contained in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygfrs2c254a x5lt2qy1 r l7 prhsen 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 ul 0do0r0oh* ztbq(r7 lm q/b9between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms 0odzuvm 00qrvqj),cl8u m7 ,+ngtgu3 speed of an amino acid whose molecular mass is 89 u in a living cell 03ltg n)ug7q u udo, 0mjv,r z+08qmcvat 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 written P) zit: ww8jy9a2bh;da = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uranium, 7k 0s t4o33 d ;(ej pwtj99jmcaqc;wwr$^{235}$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 phasdr tx0;,fw:r7poskay xig.k v+*a: 6 wes can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure is 0mjr 12a fub.+pm.rm l-.01 atm and the temperature is (a) a+l - frj.u2b1m.mmrp 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on an+2:iir4g d 56l:ggsb en ry*qj9k;xq day when the t9*:2yqd 4ibg5 6xljq gr;g k sr+nien:emperature is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place whbo:rr 50 hvg+.*22lezuhokzo4wx( up ere water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a part wj5y2cn84om*; zvh qficular place in the mountains is 0.72 atm, estimate the 2*w8y jofm 5;cnzvqh4temperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial p2gxk e6vhplx m;5y8/l ressure of water is 530 Pa and v2exg6x8 k/ ;5 pmylhlthe relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when thrfilz /mg-+cb *:sf f6e temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker6 rhibsh)m3 elaw id99v3a q3; if the water is boiling a ls9h 9ar;veabq3633m i)w hidt 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 oo ;y-rmo2w fnc d,o7-tf 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 pwh aai59x. k7voint 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 (seee ok+tab 6n)0h Table 13–4) to diffuse a distance of )h a eb0tk+on615 $\mu m$ 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 intervc4 *k-a)rx u o1xm3orior through tiny tubes called tracheae. An average trachea is about 2 mm long and has v -* oxou rr1c34)kxmacross-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 caliizk8fh r 0swj.o:0sd:brated 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 hj 6yg6l 6sc 6bxl8cx2las been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at nor,pf5c.h 8x1hku fo6n pmal room temperature. How much error will be made in a recipe callinghp p1 8of.xfcu,h5 kn6 for 300 mL of cool water, if the water and the cup are hot, at 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a helium gas cylinder is initially 28 atm. After mg:zb/a*6dlp 079vk.rb lwkvg any balloons have been blown up, the gad/gpgv w 9k6 arblz :klb*07v.uge 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 length 6.5 m, width 3.1 ohc-j tb37nac7zhu86m, and height 2.5 m. Assume the temperature is 27htu8c o zhbj 7-c6na32$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about one atom per 8wkc*jyq go-gp*:+ tm $cm^3$ 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 ;/sbehq )u(peavailable vacuum techniques is about;eqeb u)s/ h(p $10^{-12} N/m^2$ 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 bel* ,rdef9yfw x7ow the surface, to what volume would his lungs expand if he quickly rose to the su* f9d7yf,x rwerface? Is this advisable?    L

  A space vehicle returning from the Moon enters Eam:9 ubbq8zox ;rth’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 seen as a bright blaze upon reent:bboq mu8 xz;9ry.)    K

  The temperature of an ideal gas is increased1+vb9xu8k); 2 nkt: io mw;b) eytuwfd 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 olmu 4vbd l )4 kl4+)yyo5/gmru8lolr1 f 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,dxwwex7:pfze4:xt : of atmospheric pressure at the surface of the Earth, estimate the total number of air moletedxwx:7 :w4z,efx:pcules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contpvv2 :8cw1ymqp 0 c0hgained 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 = 2000c)t1,zd )omq (c8 pgf-fhcqb5 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measuzc8,(cb1q)otdqc-h) fmfp g 5 red at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats inl8/c0kdcp (rqhg 2gb9 swn+leeh;4l3 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 gasolc5 07* gybdd0vl)tsd sine 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 arou w0b04psib+ub 2 l p5mkprn8m9nd 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 ont;plsve +o0 hmv52 xz0io a glass 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 in thenj12yo xylu /):yrx 8e 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 ij-ldav* lc:(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 )d007k nexcv gis $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennis balls thrown vertp u k/dile:sns,bq3+ frj99+q ically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are +/ nur if:9 qjk q,9bsledp+s3thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diametu0gtsu/ -.,j 5rqgxkf er (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 perfecgg5.t urskjfxqu0,/- t gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor prap-hx ue/5) qnvydr-tvs- -k( essure in the air on the following two days: )t/xhkd--q ru(nse v5p--av y
(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 wh5onfyv6g/1jx /de2u -0invck en it is a so20 c yju5 gn/ki/1dfovx ev-n6lid deep in 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 d* d 6;p;miazrq8ng+ gthat, for an ideal gas at constant pressure, the coefficient of volume expansion is equal ;gin+dr8zqpdg; 6a *m to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.

  In humid climates, people constantly dehumidify their cellars to prevent rot aywc* uxw ;z49qnd mildew. If the cellar in a house qw;z9y* 4xc uw(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