Which has more atoms: 1 kg of iron or 1 kg of aluminum? 5v9 q o zw9snl+0s -,xelq2bfbSee the periodic table or Appen0fo9ls 5bq2en, b- svxq 9wlz+dix B.

Name several properties of materials that could be exploited to mkhjn.:byr0 kuq7 7gb,ake a thermomete:b7k bj,n7 0 .rgukqyhr.

Which is larger, 1 C d(ow8 mgc o 8rm)yg5( :ej rvfymt(,1f$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in z*w:zxpcsl,x /fof 05 thermal equilibrium with system C, z fw0z:scpo/ ,xx5f*lwhat can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron.5 s25) xbk ujeoz.lcbxpk/+2 u When heated, the strip will bend. Which metal will be on the outside of the curve? [H5kul)2.eopjbzxc/5k2+ usxbint: See Table 13–1.] Why?

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

The units for the coefficient of linear i hoand+z3o2,w d6h o7expansion $\alpha$ 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 0q n nzhn)49x07imeg oof a simple thermostat used to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different moe9zn xn) gim 4q00nh7etals 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 can be set at different temperatures.

Long steam pipes that are fixed at the ends often have a section in the shape of 3z(kuvlj4yem, ll,s f7:w1lp a U. Wlwe,jk,3zm7usp fy4: vl1( l lhy?

A flat, uniform cylinder of lead floats5 :ic zm7 y:ue5+pieue 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 therma o)ihnb*btz 5 9sl177dsavs 5ometer is first placed in a hot tub of water, the mercury initially descends a bit and then rises. Explasovlsb1 9*s5 da)z5nha7b7 it in.

A glass container may break if one part of it is1t4g 2swp8/hh,sehvs5mh r h6 heated or cooled more rapidly than h5ewphhmts18hg , 6sr 4/2hv sadjacent parts. Explain.

The principal virtue of Pyrex glass is that its coefficient of z7/8pt7 rv1r j:ysf7wk 3kuwklinear expansion is much smaller than that for ordinary glass (zw 7wp7rtku/1fkr 38ks7yj:vTable 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate at 2gw gn; 0sc)n z.jxwkusvg(d :.0+ t(yb0 $^{\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 fr3y sh)qq*5c4ulu.tg u8 bo,p,n g-uits bottom and top to bulge so badly the can will not stqu,q f5l*y ouscgt),gpr -n8u34 h.uband up. What has happened?

When a gas is rapidly compr5nqgza; ex 9uobk*+hbn )5v* aessed (say, 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 qh*eubo )n *nk55gva;x bz+9 aparticular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerg,fkb 9secrqt lks5(**ed in water increase or decrea*9*rfkk,bs (qc5 telsse if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory 64v) o5lm cteiov+wy:and the relation between average kinetic energy and the absolut 5:t oev lo6+mcw)iy4ve temperature.

Explain in words how Gay-Lussac’s law f w:l 0gz p +mtt+)4kuv 4ji.sungguc((ollows from kinetic theory.

As you go higher in the Earth’shb4ee 9r/ mv+bts cun9ec w+/) atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speo r ekp+vqf;n *n5jd; k*z,gq.ed an object must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the Earth due to the Moon’s smaller mass. Explain zq+ek*f n j*;oq,d ;r5k.v pngwhy the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What can you inmnar3x5v 9g( ifer ab5a9x3i vrnm( gout the molecular properties of one relative to the other?

Explain why a hot humid day is farhn ..djahy21s more uncomfortable than a hot dry day at the same temperatur.2 1y.sanhh dje.

Is it possible to boil water at room t(9x rs xzist77emperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is ,kj50a:oiy;jsv ls0w -ww4 kothe same but the humidity is different. Which is more dense, the dry a;j0, :y o ww-vj5ws0soi4kalkir or the humid air at the same T? Explain.

Explain why it is dangerous to open thl5/e.s7fc rct 4b/v1msd9zif,d3p fs e radiator cap of an overheated automobile engineprdb1e/ sfcd3t vsf/zs7 ic9ml.4 f5, .

Why does exhaled air appear asq eten;ns 2 zrz57mwac-;4ve6 a little white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-graqodq6c,yg+l-fiurs13 m 67nm m copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number y -wn jt3y -z pfkai06b)cq1k8of atoms in a 26.5-gram gold ring compare to the number in a sikpy-zi anjc0fy)8k 3 t -1bw6qlver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsius/eean o m2 n6oq93:oua scale?nenq a a6o9m2o:/3 eou   $^{\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 recordekb(j9r( pzh9 vd are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

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

  In an alcohol-in-glass thermometer, the alcohol column has length 11.82 cm au3( + lo9jhxgi,h ycq82+ytd.7uw ojg t 0.0 .yxg+ +wu3 hojcju2t g8qdh,y9io(7 l$^{\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 irw9)t7c 6v rzvs built 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 (f nba2j8 lq2-d:i x.btegu) ciron approximately 300 m tall. Estimanxcqa(bgb:e2.diu-f 8j)lt2 te how much its height changes between July (average temperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, rivets that are larger than the ridqke7n73f9w*an ilc tg v 42v8vet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in thenvw7vcandl q 3kt8f2*g97e 4i 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 4 aag- evbno) vwppqd36-sx6, 0 $^{\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. Whatizevya*8ld7gp-a+k: wb px, - will be its change in volume if it is heatp b i,lge*+pxk7y:vwzaa d 8--ed from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL of water at 103 usisa/8k9ss 0.0$^{\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 of water at 20 p -pohs+e7kdxiy5;w- $^{\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 20 8s52;*ugvxqt y0/ sf )*bq pzcaz 9oes$^{\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, t;+ sv:n( wi8tu2utajp80y xy narrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximp; asyt8wi(vun8u jxyt2 t+0:ately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the densit9q jqqt33d b,4g*rwtn y $\rho$ 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 paagk-;6:;j aov f c wzjc+(ff*u /ey;has coefficient of linear expansiu/(e:jc;caagf;wv +a6-f o yz;pkfj* on $\alpha$ 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 isotropipgz r.h7t ( 4, 7tdr7llfdplshs9; 4occ solid, $\beta$ = 3$\alpha$ if the amount of expansion is small. $\beta$ and $\alpha$ are the coefficients of volume and linear expansion, respectively. [Hint: Consider a cubical solid, and neglect very small quantities. See also Problem 18 and Fig. 13–30.]

  The pendulum in a grandfather cu20k,d lze*fl lock is made of brass and keeps perfect time at 1e2 lzfk*,0 uld7 $^{\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 thermox n8cu7y5sn9c ewy e1;jmdy;1 meter has an inside diameter of 0.140 mm. The bulb has a volume ofw9;e1 sny;1d ymc x87uy nc5ej 0.255 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylindrical wheel of radius 0.41 m is rotating abrxv5zz;xc.h bi 24+oz4q; dvbout its a r oz qz+;2x;zvd5c.vh4ibx4bxle on frictionless 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 fclaimu0z44 : sn.j995idl sn desired length when at 15°C. How much stress is required to keep l4 n.lsj9 n4c5i0 d zs:fiuma9it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sebs7cy t/3nn4ht;dujizn 2+ i.ctional 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 cl ;lvqzxo 4+f gq8m5v1m 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 temperaturm 3h8yhdpq7mc : ipo1-xpe07b es 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 Fahren+abv)u,wgn2kr (dcw1 e1ym5 b heit scale?    $^{\circ} $ F

  Typical temperatures in the interior of t7s8h4 3qwu3lhbkpz z/nouk) 4he 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 /pa8:af8kjdrpet6mnlc4r8 vx87 y-m a temperature of about 2/ar8e mkpv8pc 8:mj fyrn 7-6xdt 84la0$^{\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 id-zlw -68 hno 9ncmy/aueal gas law.    kg/$m^3$

  A storage tank containsg ,rpq nh2 h06hu*u*rx 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 nitrogeux;:cg hy mo,r9j*z5zzd+k o5n ($N_2$)
(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 i+w ;v l1zwta2zs 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 ga :7vi pn2ozuo5s at 385 ou7v52 noi:zpK?   $ \times10^{ 8}$Pa

  A tank contains 26.0lm pcxs ssl0iz40*: 9l kg 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 li*q8 r qwhglnb;u f7-kf;()pvsft by heating the air inside the balloon, which makes it less dense than the air outsid* wg;f8; nqp( q)lvb-f7hkur se. 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 at 15 (w o 4b vgelh 7d*cj;uuhf16h,$^{\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 atn 1c7a9 fcxn3q8g 1bnu 18.0 $^{\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 esc lbd;f4/ cxq;bapes 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 number of molecules ,l q.hpvuz()mvlfc q (aw55g;xlef))/ $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water arek uf0m 0+ynafe+:m-ru there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) mole +awshn-n.r e1s,    $ \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 ox.-;rxj w(up 3 ,zxyz5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L breath 2l,5ldue( *y7jq gfvrx ess9 zkw/p7)you inhale that were also in the laley)2k uws qf xlgr pz*d9,7(/jev5s7st breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the averaghrwi ;m0v6),n yj7o,*yk c rgje translational kinetic energy of an oxygen molecule at STP?j;6yw r *0o,rg nhc)jk7miyv,    $ \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 nearbq() 7gc1 igyd(+phx u the surface of the Sun at a temperature of about 6000 yib((ud1cqghpg+)7 x K.    m/s

  By what factor will the rms speed of gas molecules increase if +s36ate juz 34t rf3nhthe temperature is increased froztst+4aju 3h e336rn fm 0 $^{\circ} $ C to 100 $^{\circ} $ C?   

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

  Twelve molecules have the following speeds, given in units of km/s: 6, 2, yslfos1)s0( .6p azvp4, 6, 0, 4, o6 la)( fppyz01. sssv1, 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a3qxwy 8e7wg :*xn j*xn 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 avu8txfe(3yh:wx * r5 p gas is doubled while its volume is held constant, by what facto fu8v(h 5pw3yt r*xxe:r does $v_{rms}$ change?   

Show that the rms speed of moleculeovn+c d hhaa;ieez(z -98 ;pu a9gp.g,s 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 gases aa n3 b55k lkso(o,g5u+vag854hecchh ycb 05 ot the same temperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecbg 4kosy u(h+lo5 cc583ac ab5e 5, vokh0nhg5ular masses.

  What is the rms speed of nitrogen molecj6l5 l9lg ig9eu6d+ fs-adoxmg r25w /ules 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 oxy .t-e t lwrxx1vx4+7ihgen molecule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance between nitrogec:ksj1g t:y b; daxvrm3r6q 4(n molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 uxcy, b bd9)1dl3a7 +ppzxd ptu (v7qo8 in a li tbouxb,pzyd+179dpv(pl7 8 3q xadc)ving 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 gay* ;-rbxb.jqd*jky* o*gwbh:s can be written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of ur4z. m7d/ iu0dqodah6hanium, $^{235}$U and $^{238}$U (the superscripts refer to their atomic mass), can be separated by a gas-diffusion process by combining them with fluorine to make the gaseous compound UF$_6$ Calculate the ratio of the rms speeds of these molecules for the two isotopes, at constant T.   

(a) At atmospheric pressure, in what phases 9zympq0o 2lf,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 ic y ,pjhjs,vdsxk2* 3 f34c.0hzhcxb 4s 0.01 atm and the temperature is (a)2phv c4 ,jj3z*b 3hcd.sy,hf 4csx0xk 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity isf*gzlb7-f m bh:u 6a,ayqc4(h 50% on a day when the temperature bba,z:c-gmu 4f7 (l*hyqa6 hf is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boilm/v0kn,xwb *ick) q-us at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72 atm, esn y )c) k(6ewjg ew;tiplvyn,:09 n83btmx5 dbtimate the temperature at whi80 9et (b5ib njxtg: c,n3 wevnwpd);ym )lky6ch water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of wat2ft e (.9o0popmersy ,er is 530 Pa and the relative humidity is 4t0rype po,.(2 fsmo9e0%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a r.k8 xlino.6 oday when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside6nfltevyjph(+ 51eouyh cp ju64a5ay5 .m 2g+ a pressure cooker if the water is boiling at a tmep6+c5 l pt o 1ygyyh2a.j4n6hjae( 5+u fu5vemperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of v:43 5sqc :x5ski7y ohkek*ptfolume 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 of 5 hx z c:b.*vekhvqdo5*/0rt:n $^{\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 nek ;6i9zmtq , *bggihw4eded for a glycine molecule (see Table 13–4) to diffuse a distance of 6,bgq 4 mg*ih;wzitk9 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 y.ubyv 2.,wyp the surface of insects to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has cross-v yp,ywb2. y.usectional area of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been calibrated aao6v45 ef2;i7q 2lnz fhax4kut 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape measure has b h;7vp+o1co 8db/cvi reen 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 calibrath1wo6adc*4 pn 3o5niged at normal room temperature. How much error will be made in a recipe calling for 300 mLw p53a*ico1o dg64nn h 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 initial: 5icgl 8udow7ly 28 atm. After many balloons have been blown up, the gaui85 : docglu7wge 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 m( wuta-xb8l+sa)eam 8 , and height 2.5 m. Assume the tempe a8ea(bu8axw+)s-t mlrature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about one atom/t0quztf: 056l a*c s 9luucnj 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 u/q/ojmi v)k9 jsing the best available vacuum techniques is aboutiqjv/o/j )km9 $10^{-12} N/m^2$ 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 wmlp,v,;fv m. ihen 10 m below the surface, tolm;fm.pi ,v,v what volume would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at n8fn7 mi86yu +o-(qikd6 s /w6nlhg qpa 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 mus+pi66q h8m/ fgdin u-(wsl 8 nqn6kyo7t 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 f7 tps9awv :it2rom 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 770mgzw/, w- iapbxrjyi.3x+x4t6i k 8tp5$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at the surface of th0k4c3le3 vo7 07fv.rpgg6ffqjx r8x ve Earth, estimate the total number of air molecules in 8f.fx0ef3vvgpkrvl 47rgxc o 7 j3q60the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained a jy6qz(bw.nzajy:8 6 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 gaugcyx9vn) q1 rp2e pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, meas)2c nqvxr19yp ured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid mercury atdg oy df;u+,nnz s/y6 va+*ld0 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 gasoli:ljjd8wt-p8azd 5l5/gyaih*ne 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 around the Earth’s equator at 9jhtzd)q d:37 ( i*gqogsxt,d25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto a glass;l90a.c m c- sgje+r5kslx6vs 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 (hxx:a pj:ty9 b)9koe in the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when f v/*e-t(r23 rdlvtyfiully charged, has a pressure 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 Earth is :saya)te 5d * eiily;s1m)j-d$ 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 suspzzzz ka8h2 t/3lopgq4,,nz k4ended against gravity by tennis balls thrown vertically upward at it. How many tennis balls per second m,q,nzzk 3o4t2kzl zh8 / a4pzgust rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diamet97i lwq* 1zqe8hyoo)ger (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is 81l zqyowqig* e)oh97constant 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 o0 fsf*zuch5 -water vapor pressure in the air on the following two days: zs ch0o 5*f-uf
(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 aybcp -vjj. )i7t STP, and when it is a solid deep in the Earth where the temperature is )j-p v7ic.yjb2000$^{\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 t( tj-k,: 8 sxpd+okqtno show that, for an ideal gas at constant pressure, the coefficient of volum+k:tqpj, 8to sd-( nxke 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 dehumid4fphs1h txdsz;x -:h: ify their cellars to prevent rot and mildew. If tpd ths;sh fxhz1 4:x-:he 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