Which has more atoms: 1 kg of iron or 1 kg of aluminum? See tp b9:5 say63z eq mvfiv//nd-hhe periodic table ovqi9y hped/m3-5sbf /n vz6:ar Appendix B.

Name several properties of materials that coul8izagv6.2py p d be exploited to make a thermometery.v 6pgip2 a8z.

Which is larger, 1 C 4wz) fdn(.v1,g6jiqpdf. lbc $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal eq0d:w ;mr,y)n zlu)zsik:x vi:uilibrium with system B, but B is not in thermal equilibrium with system C, what can you say about the temperatures ofnm:)wsux0 ; )dz:yi ,rlkv :zi A, B, and C?

A flat bimetallic strip consistg cz*h0jco8qpm5 vg: :s of aluminum riveted to a strip of iron. When heated, the strip will bend. Which metal will be on t z *jq0mcgo c8v5ghp::he 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 lifp ze*/1xb .ww. iog8hnear 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 us2m(y9k0svt9 xn m4bw* w;/ -rhficpaved to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how it mrb shkwp2m/x* 4-v9cw 9nvtyi0(f;acan be set at different temperatures.

Long steam pipes that are fixed at the ends often f38 gf6zasj l, ve*k:nhave a section in the shape of a U8f*:alz ,jkse6fv ng3. Why?

A flat, uniform cylinder of leada37l hg15zz.ls*x fr l 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 pyvd9 6t8x ) 2gfbc8 f5uip,iihlaced in a hot tub of water, the me,u5i8g tdi8pb ffv)y9 xih2c6rcury initially descends a bit and then rises. Explain.

A glass container may break i9m9pq8yb5yj v/az6 gk f one part of it is heated or cooled more rapidly than adjacent parts. E 6z9jb a/5 yqpmyg9vk8xplain.

The principal virtue of Pyrex glass is that its coe5)yfp;j.+ zq85 ,xu bwledb 92hwtzdlfficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat r,z.j528hp9;dwu w zllb+ b tf)5qxdeyesistance of Pyrex.

Will a grandfather clopm 5l+q3hg32p jixqe 9ck, 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 sof-gvz/g ro,/j badly the can wi-r/g/ zjv f,ogll not stand up. What has happened?

When a gas is rapidly compressed (say5pifg :zn.zu9gkm (8y, by pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noti9u:f8k i5(zym.n gpzgng 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 *9hhi0wzh e-jor decrease if the temperature is increased fromhhe wzhj90 -*i 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charleii,u +w( fcs, ds8p:)uxq ji)ms’s law follows from kinetic theory and the relation between average kin8jf,, + wdiq ix i:m(s)upusc)etic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinet8nh)ffx yr2gw 4+*ikbic theory.

As you go higher in the Earthu/hoizx + 0in,q :byf3i48 iam’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refe z )es:xdt9 czg2ekz*(rs to the minimum speed an object must have to leave the Earth and never return. The gez *x9 tz:kzs )(2ecdescape 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 practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What z+.p1j- jt u absnh81qcan you infer about the molecular properties of one relative to .n+ustzq jb1-8a hpj1 the other?

Explain why a hot humid day 8).evolg:( g 2d my,..qgg kfl- jstfyis far more uncomfortable than a hot dry day at the s (fkqo8dy)-gy.v gl g.,tje2g:.lsm fame temperature.

Is it possible to boil wa k v)6zdrb.;uyter at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humidity is difuzf985eop,e/5dl/t cx ejwz-ferent. Which is more det-e fd,lz ox9 j5upw ez85//cense, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an overheated afp ,hnke i(cbn)p d4/-utomobile engine.)(dbpp kicenf 4h/n -,

Why does exhaled air apu1 5xvx9iw:pr4j ib 9v4+sssg pear as a little white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gw99 w4tcgu okj +6j,zeram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold rd5 /.,jvc6pxp ix a7mling compare to the number in a silver rin.,/vx5aclm px6 dpj7 ig of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsius :iov *wsu7 a(cscale?7c: w*u vi(aos   $^{\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 lcfkekm i ;q)0e6 p.;tsn- (vvtowest 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-glag;if y /y zqd87.hk7lbss thermometer, the alcohol column has length 11.82 cm at 0.0qyhfg8 bdzyki7 .; 7l/ $^{\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 b370ux, uu4qsj ksnqd8qoojmh95 i( *luilt 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 td(,et7x plx0sm2: a1*uhh/ ppy*wv15uql oe wrought iron approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and January (average temperax 2tw5se0 l*,/dt7(ov p*ha qul11h pyue :pmxture 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 6rug ;fkz0 )yvc vef;n 0og*20 jn-bzmlarger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter at 20 czggo0efnyj- 0 rvk)*206 nu;zm vf;b$^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water uclby5qn+fc 48.ny/ bat 4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be its change in volumem.+fu* g, 9we7ovpho i if it is heated from7efg9*i,p hmuo o.v+ w 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 1rwyd6 /8m0l-:r uuzer00.0$^{\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 mL xo: ue8 xwp).vof 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 p 3 )fwteq(rk+zlaced 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 68j -6iiix jvxg9xml wlvp*5)yt7 k2 bin essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansiog98*-i5xt6yj xl7w l)v px26jvmkbiin $\beta$.

(a) Show that the change in the de.vf x 9x9b+d nz5wik3* d;jsxjnsity $\rho$ of a substance, when the temperature changes by $\Delta$T is given by $\rho$ = -$\beta$$\rho$$\Delta$T
(b) What is the fractional change in density of a lead sphere whose temperature decreases from 25 $^{\circ} $ C to -40 $^{\circ} $ C？

A uniform rectangular plate of length l and width w has coefficient of lineaf8kvv3 dpjb9c+dhyy,z 1hod/1cc s4 /r expabhovs cdc9 +/81yzyh,1kd3fcpj 4v d/ nsion $\alpha$ 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 solid, 0+) d6z2x ;,omc*4q)frxvf0peuvprkpk ; gak$\beta$ = 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 tim+wwg w5y qt 0d7gh1th( y(mi5qe at 17 wd(7yt1qhmht g(q0 g5w wi+5y$^{\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 04 k3*-srvy+gnp;okt e.140 mm. The bulb hork +kpgnv-4y3s *;e tas a volume of 0.255 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylinq4s a/ 1vdpos1drical wheel of radius 0.41 m is rotating about its axle on frictionld1svoq1sa / 4pess bearings with angular velocity $\omega$ = 32.8 rad/s If its temperature is now raised from 20.0 $^{\circ} $ C to 75.0 $^{\circ} $ C, what is the fractional change in $\omega$?   

  An aluminum bar has the desired led+ b0k.(n ii;/wxtg ozngth when at 15°C. How much stress is required to keep it at this length if the temperature increase gx; (+ibtnow/.kzd 0is to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectionp29eyfb.vn:rs+pg3b-l w lml; 6 ml8val 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 9 hypvg0ini.wgjp 6)g+hi68n1qiy; f 134.122 cm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on the K4 pm02crbomxml( ,d( delvin 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 tempf) s0so9ky. bs b*u0jnerature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are aboutz 327)mgygw +6srl l-9yk-hxbra -hh i(wjk,f 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 engiaosbbyavn 0/8s4o 2. sne, air at atmospheric pressure and a temperature of n2s8s0b4bs.o ya / oavabout 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at STP using the ideal gas law uu:qp,xs 8qdgakzp d9 8e*c-,1a 1ibg.    kg/$m^3$

  A storage tank containe)l zj9p eow-2tqex- kd4r1,rs 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 nrmypc.x+pl+07 ssox,igw *kpz4 vu08 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 at -.wq2t*-56 m3ffu neml fsaj n10.0$^{\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.ud:5g)z kvc w -tsz*20idv)ht 0 kg of argon gas at 0s) :-tkzu2dch t* zgd5)vviw385 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg od gnme. b m(q(wi-9cm4f $O_2$ 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 mx5ljtl2 13/vonrk rpmzuz 4g -c b788buoyant lift by heating the air inside the balloon, which makes it less dense than the aklj2rzmvx mtr 41p cl8b3z u5-/ 87ongir outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air b ema(j 0orfd5/0 ul,dt91fmc at 15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at 18pg*cgye cf y0qwn8* 8lkpnmm3 eurb q; 8i72/1.0 $^{\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 szc 0lnhxj t,)1ea 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 number of molecdmgi y+1bppte 5y8-j n)r-4f c4o 7ivfules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many moleculesp2ptz5x :j btd):3 tyj:diji.k.4hoi?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) :34nkt uey /qnmoles,    $ \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 5w j5skkt 91ci5tm +1ai cgkc5:0l1awn.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,dfbz c 6,p0f3ydtx k4 each 2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is a,cx b3f 6dp, 4fdt0ykzbout 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of ,,w9 dtih6vve ys,.z6v m l/nfjmu b(5an oxygen molecule at STP?yltvm, vz j,6iw9 (5f enm/,6dhub. sv    $ \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 q()eaqhx :t -mnear the surface of the Sun at a tempera: -(qahqtmex) ture of about 6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if the tempe d4(gvpczo0/ h3wzw8 vrature is increasedv3hwo (d/c0wpgz4 8v z 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, gx /1lh y2 (j(rg:gxjv2dwd:hyiven in units of km/s: 6, 2, 4, 6, 0, 4, 1jg h2x :jldyd(vy2(: x1wrh/g, 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a26i u,-h c :shka:mgym 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, by whatcr6 uz,a,moymrs 54iu2 )fvi( fa 4zsr icv,(my6 u,r2)muo 5iafctor does $v_{rms}$ change?   

Show that the rms speed of mqg(-zfx5pd: q olecules 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 two gaser *17 q5nqx yvu gtv,6j+ +1 mfxy;wu;;qzsqsas at the same temperature, the ratio of their rms speeds is equal to the ix5 jf;1az ,xs6nrqys gqv;71;mqwqv+u+*u ytnverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules contained in an 8.58)zpu d bky+*s$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygen molec3 -;bq :g.p5 sr poueczx,s:blule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance between nitrogen molecules at STP juyxyzef (5br +23;yh?    $ \times10^{-9 }$m

  (a) Estimate the rms speed od. 3v;rdmqmy/ qmn +g-f an amino acid whose molecular mass is 89 u in a living cell at /.-qv3 gymdmq+m;ndr 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 wribbb fj/a ;r4fpb/gv9 3tten 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, 7z6r kd(,/3lmtxb ghf $^{235}$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 presskj 434wny b-a l*w0padure, in what 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 6h fze4eeky k (r j-:as(xii;g,8/ctj and the temperature is (a) /ki6fxjhe:e,rtec-ga(8 ;sij k zy4(90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidityvg7cu e1 qevjh5o s+vx+ :,a*y is 50% on a day when the temperature +vvhj qsy57 +,1ec xvoe a*gu:is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure atyy/x.v1 y+dw t a place where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72 atm, estimaz;)1ype id 6yepw/ hd,.)dluite the temperature ly d6.)w) ;zeyii , dph1/edupat which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day whenzzbex8.8;cfwa7 tt d, the partial pressure of water is 530 Pa and the relative humidity is 4t7f 8e,zwd t;xza8.b c0%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when th8 5npis:. i2uwaz l2vhe temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure insidev9s0mz hnl 5/nz )o zu(wv-4pl a pressure cooker if the water is boiling at a temperature of 5np zh0w 9ln) /4(vlzoms-zuv120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of;g)3y iuy/c ia)7 0*ekuod fjl 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 po1t35 im8w jxzr8(fwe,5 p6gfpkivru3 int 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 (yk)c5g1.hb yisee Table 13–4) to diffuse a distance of).yychk1 gi5b 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 interior through tiny tube n++0mztxd kdu2m.o78 ps:m grs called tracheae. An .d+ou8 :zdm2msn0k+7mg pxrt average trachea is about 2 mm long and has cross-sectional area of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been calib(, vw33f z1s9sa prkitrated 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+s)5(nme9y 0aph k spx has been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room temperature. How much y2m4hv bxsv3pmcjzr2 n.1 7 4nerror will be made in a recipe calling for 300 mL of cool water, if the water and the cup are hop rb.2y3hvvxz4c2s 1j74nmnmt, 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 2vrl:b d 683qr;uvhq8 apm /j2j8 atm. After many ball8q mja2d/ vvrb6jlr8hu pq :;3oons 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 length 6.5 m,za : 3rrkp0 0uo.um,qq width 3.1 m, and height 2.5 m. Assume the temperature is 2qrqa ,u0:k.mzo0u r3p 2$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the densityk 1n+ nx 0eashwx)6j)h of matter is 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 attainablet wzzz ;h ; twmu2u8:g,3jpw3e using the best available vacuum techniques is about3e;hzjpmu w,gtwuw;t:z 832z $10^{-12} N/m^2$ 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 belb v/4yd:i3mam ow the surface, to what volume would hismvmia:4d 3b/y lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s ar; 1bz0+ z 4tl6pck cplx9he jni.8fr/tmosphere 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 th9keznlft+1px b;zrcli j/0h6pr8c. 4is 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 reentry.)    K

  The temperature of an ideal gas is increased froiju 0m4gzf1diyvc ), 9m 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 .zp* zyqyn:ksh.54b/7y o (0 q;z touasiqg0b 770m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure a66kn ra *zn.oyt the surface of the Earth, estimatea6k.on6* ry nz the total number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nuo -gf6y9+qu;xl,yrvv 4ye s7itrogen 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 = 2005gpr+ihtg4l1na w 3r:hs5lz (0 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow lt 5l(h3w+ps agh4n 51izrg: rrate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a hg0knbsj8c/m18 b4 x nbowl 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 gasolin*v7r 7ngm7fr0 t bv)t bj vc:x+qs)qn(e 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 f12zdl5bi .k zlit snugly around the Earth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tigh )xyhpl/kl .)m-0v apgtly onto 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 upxbp jcj:.0 2the 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 prp3f836zy;x n1 vwiqr 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 from the omvjo4v6q4qj :yejocp4;4vpg 3v ih40q(j t1Earth 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 balls thrown ver2xtd-c5v gx(b tically upward at it. How many tennis balls per second must rebound from the lid elastically,xx cb(gdt-5v 2 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 ai)(:uuvfc 9z*iw 8ut:d vr*rrnr from a depth of 14.0 m in a lake. Assume the(*)u *vwfit:rncud vz:8ur r9 temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in t6)s +vso e a4gjd22ljfhe air on the following two days: d2j4 +as)elv2gsoj f 6
(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 whn4h( sllmrsi4,rp1: len it is a solid deep in the Earth where the tempersll(r p 44sm1rln:,ih ature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, for an ideal gas at constant pressu3b); 6ranvc3wmsl vd3x9.tiv/zi) u yre, the coefficient a3vr 33/y)ls)cu 6 .xtidivzbnm; vw9of 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 dehumi gbmvgzx+ ,q5:)ni 6vbdify their cellars to prevent rot and mildewg+zbm,i v:bqgnxv56) . 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