Which has more atoms: 1 kg of iron or 1 kg of alfv x;;zem:5g+w6qs ba4s kbsnx )1;vzuminum? See the periodic table or Appvmfnxsa;;:bzk w+;zs x 5s164gqve )bendix B.

Name several properties of materials that could be exploited to make a - wah,uzq.k aih53 o6kc 4.qangkcc18thermometc5o8akq w3cn.6.-zah1ka4k,gi q hc uer.

Which is larger, 1 C v9g ((k 09l+d ou,gv9byysfvc$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermalnkitr52qf6c6 r-rrhl gk) 27 u equilibrium with system B, but B is not in thermal equilibrium with system C, what can you say about the temperatures of A, 2hui rgkrlfrt)kcq-52r6 n6 7 B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. Wm1 jip+jp,3xphen heated, the strip will bend. Which metal will be on the outside ofxpmj pj13i,+p 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 coefficih bp+r-/ li*scent 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 simple te: w we5x8xwv7hermostat 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 we 8ewwx:75vx 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 ata,p )buf/v (5(gv wxpp the ends often have a section in the shape of (abx( /f5 vg upp),pvwa U. Why?

A flat, uniform cylinder of lead floats in mercury at(i6*i8/vd1 +puwems5myc bt h 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is;j a jqd,3* 2mfqu2av po61whx ,qoa*e first placed in a hot tub of water, the me qoap j2m*,eqvo*3jdh6,au2 w 1qxf;arcury initially descends a bit and then rises. Explain.

A glass container may brg 6nry3e4v14 5 ulci2po5fgzgeak if one part of it is heated or cooled more rapidly than adjacent parts. Explagoupi34 gvey gc51z42 f56 rnlin.

The principal virtue of Pyrex glass is that its coefficient of linear expany tg( mvfq1o,-sion is much smallergy,fvq(o 1-tm than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accw m+d3vcu65 t dv ruw(25-bsc09kncgburate 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 causer i,4x q5etfjagv) 6ycio34h1oq fi39 its bottom and top to bulge so badly the can wiqi ,e4y ocvx6q3jhig9o ia3 5frt)41fll not stand up. What has happened?

When a gas is rapidly cn bu5m5s1nkwy(0zzp;ompressed (say, by pushing down a piston), its temperature increases. When a gas expands against a pisto5m bs01 k(z y5u;pnwznn, 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 dub c). 7/ reau+1irg8lydz. a0wgx7fk ecrease if the temperature is increased from 20 rz . +)7kag/clu7. 0gwe1fbydia8x ur $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kine lqu+;yq w8rt;tic theory and the relation between average kinetic energy and the absrw +tlq8; u;yqolute temperature.

Explain in words how Gay-Lussac’s law follows from kineticlcu2xhg,f u-: theory.

As you go higher in the Earth’s ati.sz;/ni n88,bhejprmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object must have 6ermjojtowh25/ f3n7to 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 practic rof2j3wn5m6e7o htj/ally no atmosphere.

Alcohol evaporates m3ycl cla w :x ;rtqt7x;fq)/+tore quickly than water at room temperature. What can you infer about the molecular propertil xla; 7w3:t+ c)t c;xrytqq/fes of one relative to the other?

Explain why a hot humid day is far more*+a*od;+ ugemjpcm y op+/ 2m+ah i+ja uncomfortable than a hot dry day at the same temperature.m++ ipau am2yj/oe+mdg**;j+ hp a+co

Is it possible to boil water at room tmks) :u; 9yf oyyxrn7.ebr-7temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humidity is difl:f2tulh7j y ;ferent. Which is more dense, the:7ljftulh2; y dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an overheated automof d.4k 0ak0t8 haxl2ojbile enj 8 a o0xldta.42fk0hkgine.

Why does exhaled air appear as a little white cloud in the winter9 ddiyv)pi: 1u (Fig. 13–28)?

  How many atoms are there in a 3.4-gram copper peny sz+x/.q6)y fgr yb4any?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in rg45 zxv4cs- fa 26.5-gram gold ring compare to the number in a silver ring of the 4-rgxfv5zs 4csame mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken tow s6)z0ah8m+pwy5h n q be 68°F. What is this on the Celsius scale?as0m8yhpw+)6nwh zq5   $^{\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 temperaturesf;maoy* :;y sn 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 alcohovd.fuj -0g3-rhba - eol column has length 11.82 cm at 0.0 3- ejh dbgfua0o- -.vr$^{\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 sla56t( ty j6ge4nisypd ;bs 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 na4ctm)to9p (f m,xwd jo16w3wrought iron approximately 300 m tall. Estimate how much its height changes between J,w9t43cwnp od xm6o1t j)(f mauly (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 rivet jbgaf5g)a :hq4 w5 2zqhole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rb fza4 5ghjwa5 2:gqq)ivet 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 4 n1q) q(1dwcvy $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be its change in volume , m )ej(v/, ujini*wcxif it is hemxw,,*uv/in je )ij(cated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filledil8 b naod)()a to the 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 55.50 mp+s,j a xp 8i 1k4v(6gun;othaL 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 v2r9 yh0lo-, k.p6tae nuj/oqtr77 m.g af2 ib20 $^{\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 canop: fytp9*0n;* th+sg:jznp g expand in essentially one direction only, sho t: ;p*j0z +fo 9pgysp*h:ngntw that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the chaz0vi; b27ih0yn;vk rv nge 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 widthyttm5xd;wh8 a2gu i:1 f (6+m+lfyau q*fc* tz w has coefficient of linear expwtuag(5iyt+ym* +fxcl*q1a u2f 8dmf;6z:ht ansion $\alpha$ 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 solzkct byzw/g 2)0jz8yhw7 ts1+tz;,xb id, $\beta$ = 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 mf7l1a crv / nm1sca(c(ade of brass and keeps perfect time at 17((a1rsvl7ncam / f c1c $^{\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 hab) n6z2fbrhs; pwg()ws an inside diameter of 0.140 mm. The bulb has a volume of 2 )f)n w bwrp(bz;g6sh0.255 $cm^3$ 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 cylin8mgjf: h/ txaf93s)d edrical wheel of radius 0.41 m is rotating about its axle on frictionless bearings with angmxf h8 3sef9jtd/a :g)ular 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 whenhva9v3bjz. +g at 15°C. How much stress is required to keep it at this length if the a3gvv hj9z.+btemperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cx- dex-g aex1ja pa1;;.mn0 jvslb 8f;ross-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 134.122nq kphc a9lqj54m+-k4*kgw k2 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 temp g cc tmf1g0+:fr0udm,eratures on the Kelvin 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 on the Fahrenhe44xgmn 9v/u koit scale?    $^{\circ} $ F

  Typical temperatures in the interioj+m jjxju: 6/rr 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 tgy3v-n5+aat )dxe c v;ezu2q9 emperature of about vte3 2y)xanae;9u -qc+v 5dzg 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 gasu om/lwa afcs7 5t6n8/ law.    kg/$m^3$

  A storage tank contains u - /zzxyc p:(spl(8bo8r uc4a21.6 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 niak f euwb8,1/itrogen ($N_2$)
(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 o1a)py 0/38qbjeqq smuq2by 3 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-L container holding 105.0 kg of argon g*vlz9js75us 6yx w- i,3uj xdwas at 385xwu wixvs,376sdy jj -ul*z59 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 dyi t:bqaljdw 0,4:/mkg of $O_2$ gas at a gauge pressure of 8.70 atm. If the oxygen is replaced by helium, how many kilograms of the latter will be needed to produce a gauge pressure of 7.00 atm?    kg He

  A hot-air balloon achieves its buoyant lift by heating the air insid. f)k.k;4x 3msadg nlae the balloon, which makes it less dense than the air outside. Suppose the volume ofnl dmg)f.k a.;s34xa k 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 dvi6zxk iy q/t7 q-s+b vl0s39at 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 1 yflqoo pvglo00l /x 3h+1b2o)8.0 $^{\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 escapekhj 8p c,ptp56s a child’s hand at sea level and 20.0 $^{\circ} $ C. When it reaches an altitude of 3000 m, where the temperature is 5.0 $^{\circ} $ C and the pressure is only 0.70 atm, how will its volume compare to that at sea level?    times the original volume

  Calculate the numberdjxw- e xu q+6n*:bu(k of molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many molecule:dmazkrja7saa b 2.j 5gf0;2e c0 ,nyss?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) :hqgr.(yys +4we h(uqmoles,    $ \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 volumerutmlv ht(le0.9c v4 -e2cla; 5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L b:gq my(o,.zs aeof;b:: szhag1o *5eareath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and1 o,;gb aa:(y:gaszzf qo: eh es.o5*m of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational ki6qz yd ek4p3q),g* x :vsu(cqenetic energy of an oxygen molecule at STP? *xd ,y(:eu6sqez4)v q 3kqpgc    $ \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 hei,7w o:5( na,ry xqxfdlium atoms near the surface of the Sun at a temperature of a7yf 5dqw(rn o ,ai,x:xbout 6000 K.    m/s

  By what factor will the rms speed of gas molecules ch4qeq1bju+k jka30pk).v 5xincrease if the temperature is increased from eca+p j4) 1h.xqbu05jk 3kkvq0 $^{\circ} $ C to 100 $^{\circ} $ C?   

  A gas is at 20 $^{\circ} $ C. To what temperature must it be raised to double the rms speed of its molecules?    $^{\circ} $ C

  Twelve molecules have the following speeds, given in units of km/s: 6, 2, 4,mvo5lsjri(2+ d ,za x1 6, 0, 4, 1, 8, 5, 3, 7jms5(2rxo +a, lzi v1d, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of moleculew)+v/em:ftc l s 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 doub vs(io8ce t)*dzi4 ek-led while its volume is held constant, by what factore v*(i8 e- 4tid)zckso does $v_{rms}$ change?   

Show that the rms speed of molecules ib-xdr77k . uomn 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 two gases cc4dd-ug8 )xhkcz xyn *o78n/at the same temperature, the ratio of their rms speeds is equal to the inver8gdcz7cxun-n cx /)ky8ho*4 d se ratio of the square roots of their molecular masses.

  What is the rms speed of nitokbv ir+r19hgq,i/s ; rogen molecules contained in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygen mol yh)8ri3bxvybg rt1(km*4 e z1ecule 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 distancw m;11kzff9p ce between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u in ay9m75 tqwp3qw)mgg+ p5 uy8g l livu9pqg wt 3yg)57 mmgp5+lyw8qing cell at 37 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a gas can be written P8qi7ij9p5/eg )g;ryekyo*h3b9 g r af = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of u)mgh1a0+qi vkranium, $^{235}$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 whatv;x.t+1rf r ua5njo3ot ke 26t phases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure is 0.01 atm and the temperature is (a)2a)lu al,*fpc 9, fpu)*a2lacl0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if tp7oq 2d wu,df *:4kilrhe humidity is 50% on a day when the tw 7l2od :q ipkr*fd,u4emperature is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water*bw c.vsaqc .; boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particulgzl9mbjmb-,v 4 xh4 6ear place in the mountains is 0.72 atm, estimate the temperature at ,6m 49b- vlg hbz4xjemwhich water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial *vw;qm0:xmhsupgie 88p:uoq 8o9 tv(pressure of water is 530 Pa and t8;ix pwo0vu(8qte: s*p mqmo9:uv8g hhe relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on q+t:ynun9bg 2a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water is m87 awf w76ckts0qa4 zboiling at a temperature of c608fmszwa7q7 wat k4120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a roovaf:i *5z4qoq m of volume 680$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dew point kjv3ka,+a 3u wof 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine molecule (see Table 13–4) to 7b b-0 mck7ua0q.zn cqdiffuse a distance of 15 7a.b cqnqcub0-07m k z$\mu m$ 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 /ncmka x-zbt w+e)v7y ss33 l2to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long3xmyn2 /lt+aessb3k )cvw 7z - 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 bee e (q:b2seuigf4 ,ykm1n 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 ht/cry6sutk.6y4ps + g u7d4mwas 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 normal room zkz5 -xb*/wijtemperature. How much error will be made in a recipbz/5j* wxi-zk e calling 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 in: qhw0svlp0l8 itially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What frac8l phwslv00q: tion 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 m, k2p k7l9 yh3rfand heigh ykrh93k72pf lt 2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter i+ xc5b) w8r8busq* egj(kl c0es 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 using tsst) f+hc6-nj wni okz5h )t8-he best available vacuum techniques is about -zs -hc)w5n8 nhk)osfi j+tt6$10^{-12} N/m^2$ 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 capa-d y+jg ,f7x6vam9)z u,nhcq ecity of 5.5 L when 10 m below the surface, to whatm,)qev6xznyu9,ag c hf +7 d-j volume would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returhx2npy (21*cojxgt j/q 6h1gk ning from the Moon enters 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 seen1xxj/62(pch yhkogq 2t gj n1* as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increased frhh5z34ff + nyg*h0ppiom 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 770m yk97 9nt/rmv d88i3ovxjg :e+x*rrfb$^2$ (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 theg)2 vo z)mi2 /op/qvfb/ zjrr: surface of the Earth, estimate the total number of air molecules in the Earth’s atmosphev / //mbo2rp) : j)z2vzigqrfore.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained in a 7m fywn- k pqkngkf0y2uyv72 8m 4,7.zc.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 pressu)hgbn6+ *oixe re = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant ieg+6* hn)oxb at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid merl:hfrp p.6c4,4h f pa 2tp+enrcury 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)sni smy+uv .f/zo0rf6qjv9j. (p0ir 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 snu56ew;i 9drlu.w * tmaq9ks26vxhpag. gly 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 r 79yqd ni)9dxso jfm23 aib9-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 the 0bv .j+-0om(aon gg1f2bllfu 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 prkhd9q9 *f. rh3g4.(j)pf g6aajf tox ressure 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 frok5kp8ic0 ar tsfs :,d.m the Earth is $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennis a5 r:ik*t)tg ;osw.zs balls thrown vertically upward at it. How many tennis balls per second must rebound fromg) t.*;zwk st:irsa5o 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 3.00-cm-diameter (spherical) bubble of air from a6g (z2qsf5cb r depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas(56z2 fsgqbc r. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the fom)5ep/. c 1s*,k nxb x:s cef9sp9hhswllowing two days: be.,9:w1pe9*nh f/5scxxs p)ksshm c
(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,p9l * jgwhpz 84mt3 yl9b(f(uj and when it is a solid deep gj(pbm ly4tz f9p(w8*lj3 h9uin 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 th z(pf2 *3x.eba* gjxx4 +hm-bmn vswr3at, for an ideal gas at constant pressure, the coeffici(swbmgha xb3 p4n*me * vxz3-2jx+r.f ent 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 dehumidyi 2h38o0/a bc0whh(z9diu mc ify their cellars to prevent rot and m(y0d/2mzi chwb o3u h9ac80hiildew. If the cellar in a house (kept at 20$^{\circ} $C) has 95 $m^2$ of floor space and a ceiling height of 2.8 m, what is the mass of water that must be removed from it to drop the humidity from 95% to a more reasonable 30%?    kg