Which has more atoms: 1 kg of iron or 1 kg of aluminum? Se (l3vptl8i ev)u-pb2 (v8mzhe nvlt0)e the periodic table or A2 plv h npiv)b(ve80tm8lv (zlu-3)teppendix B.

Name several properties of materials that could be exploited to make):e+x ,ukfqn q a thermomete:fe) qx kun,q+r.

Which is larger, 1 C rxi 6lpjaya7gbfj 4 4y,1*m8o $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, bov f(ngzo2 2+fut B is not in thermal equilibrium with system C, what can you say about the temperatures of A, Bf+oo2(fng2 zv , and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. qm2rqk 9cm7ht * 2ote.da7 (hy 6sxcsjl9:g7n When heated, the strip will b79 e dsm:tyjon sch2 *k79 q(ax. 627gmctlhqrend. Which metal will be on the outside of the curve? [Hint: See Table 13–1.] Why?

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

The units for the coefficient of linear expansoym x( aa12x4wpw af,4ion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple thermostat used to control a25udiwq02d 6otc6dj l .wx4kvm( qm.o 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 2tddw5jd m2vi0qc(l wok. m6.o 4xuq6 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 /h7b0 b + l.okipzt)hgthe shape ofgt hzoli7h.)+bk0/pb a U. Why?

A flat, uniform cylinder of lead floats in m5, b31yq ii)j0r uc34uqb7od dq w2jzpercury 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 plv;0cmcjmhtx6 :av(k9 n ff*(d2 ye(wbaced in a hot tub of water, the mercury initially descends a bit a (c v;yv d2( mwmehaj*ftfcx:k69( bn0nd then rises. Explain.

A glass container may break if one part of it is heated or coolemouba l p8zj-ufygt314q -)q 2d more rapidly than adjacent2 yu -m4g3z8a lub-qq1pftoj) parts. Explain.

The principal virtue of Pyrex glass is 9*hn q4+iydwdvczg+ ; that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise d wdc ih g9nz++q;*y4vto the increased heat resistance of Pyrex.

Will a grandfather clock 83 yuxw0javv7tg;/hht/80iftmwz h8, 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 atx wokiu9b*.wy:(ta:75 fe89u/w6bh luewccause its bottom and top to bulge so badly the can will not stand up. What has(wu6 ua:hwle f ytwx b/ek9 :.oiu79tb8*5wac happened?

When a gas is rapidly compressed (say, by pushing down a 1e)/5dx)vc,ec ysfsk piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike /)cyk s cx1s,v)edef5 the moving piston.

Will the buoyant force on an aluminum f0y 0fzjp(22f0v j gwcsphere submerged in water increase or decrease if the temperature is 0(00j 2 2gwzpffvjyfc increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theol2p;afl t6b) h r.y5giry and the relation between average kinetic energy and the absl;t6lf2. ha ibr5g)pyolute temperature.

Explain in words how Gay-Lussac’s law follows from kinetic1dxmaobt g/8-xc;x h 9ip)2vi theory.

As you go higher in the Earth’s atmosphere, the rqark ct6ij :++atio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to thb1( x2 q+retwhe minimum speed 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 why the Moonbhrw(t1q x2e + has practically no atmosphere.

Alcohol evaporates more quickly tn 58j/c 6)fk(jj3g ekhmkh7 ofhan water at room temperature. What can you infer about the molecular properties of one relative tn 3 mj ekj75g oc(f8f)hkh/6jko the other?

Explain why a hot humid day is far more uncomfortable than a hot dry dawo;a ;co4si./yh6 byx y at the s c ./;4y;obo ixywhsa6ame temperature.

Is it possible to boil wat dd 76y ul:gk,(wsh)xqer at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the huup( *xl -ar1tnmidity is different. Which is more dense, the dry air or the humid air at the same T? Explnux1ra lt*- p(ain.

Explain why it is danm 2v)i;ib +lqmgerous to open the radiator cap of an overheated automobile en;bl)m 2 mq+ivigine.

Why does exhaled air appear as a little white cloud in the wintelgj9g)c+k( odz.-c* qpx0 ku yr (Fig. 13–28)?

  How many atoms are ther*f/2 iktcalhwyu ,e+6 e in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the number aq62(pa-4aez+j5mr g u l:vtc in a silver ring of the s 6m+ue lcpta-a2:j5rgav q z4(ame mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68.ay1np-u gq-j ; eoal,sqn),m°F. What is this on the Celsius scale?qplyo--q,) sg.mna1j;enu ,a   $^{\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 reccvajzt6jw pjr v;4yj0vb- )*3kp h+:yorded 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 alc8zv a-8rnic+8i xrj-r ohol column has length 11.82 cm at 0.zrari-c rv8xj 8n8-i+ 0 $^{\circ} $ C and length 22.85 cm at 100.0 $^{\circ} $ C. What is the temperature if the column has length
(a) 16.70 cm,    $^{\circ} $ C
(b) 20.50 cm?    $^{\circ} $ C

  A concrete highway is built of slabs41xq8 tz/nx ds 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 w);54xur1lwz u(r6uce.ff b jgrought iron approximately 300 m tall. Estimate how much its height changes between July (average1x.f4e uz5gur 6r( )jlcuf;w b 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 hole are ndw,e gbddg /,1cxm/*often used and the rivet is cooled (usually in dry ice) before it is placed in the ho wm*ng/de/g1, b ,ddxcle. 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 waterjj th q6es ;02aif(n4e at 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 bmwid /4li98 iq mpzc5;e its change in volume if it is heated fromc4di;m5pl 8z/w mqii9 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim )y:r o0/fd pv:ghut+ewith 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.mp1d 7hyj2iv6izlp p bll2-):50 mL of water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to be placed ifm28 z k6bgw08)petb hlyz5, x+fljv3n 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 ing 1 b;e+b,dgru essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to the cod1egb,+rbgu ; efficient of volume expansion $\beta$.

(a) Show that the change b -f /th2 m+t3mhkbxry0cd (m8in 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 lew.03bxi wz ljj7yd4v8 ngth l and width w has coefficient of linear expansion 7 8w0ibvdjjx4 y.3lwz $\alpha$ 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 solt7t fme6 s;4u7g8; ;bnakbjfaid, $\beta$ = 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 brastt:9i+wc) zui s and keeps perfect time at 17i uw+9ticzt) : $^{\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 thi+f+5pz6m;wqgxsk a* ermometer has an inside diameter of 0.140 mm. The bulb has a volum*ik;w+sp xzgm6+5aqf e 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 cylindrical wheel of radius 0.41 m is rotating a m6(mb/gss.mdbout its axle on frictionless bed.msg6mbs m(/arings with angular velocity $\omega$ = 32.8 rad/s If its temperature is now raised from 20.0 $^{\circ} $ C to 75.0 $^{\circ} $ C, what is the fractional change in $\omega$?   

  An aluminum bar has the desired length when at :z-m r 58sct yxuhgqrrw:+hm(-uc84h 15°C. How much stress is required to keep it at thisru5uw(hr :mz-q4g -h hs8cxtyr:+8c m length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-secti stlzf2m9rp*/ /8cl oew96oqz onal area 0.041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 134.122 cm at uvp46o( y( igu ,csf3s20$^{\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 temperaturvu 6f/bibb u;f tznpc9p*:m(n;ai: 1yes 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 tht,lk.. em9oa viyn 2/ve Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in thehp4iskqwtqxlhvo3gq,1-yo m 3l/x1 9 5i75eo interior 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 temperature 5qx(q, ctp1bv of about 5p1xq tbq (c,v20$^{\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 lh74*;ha 9hp8s yqp n lyu+r (3bsu5omusing the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg ofo2.a*sbhf .t/ j+(e m/qr rhch 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 kgf4 cyb1)j gbmm*e+*mo of nitrogen ($N_2$)
(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 a hs3dg7f(a 5gjt 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 105.00s9)f,85f2z 4nl mblem7kica 8g bmue kg of argon gas at 385 mbfm mnge78lb uf4sa5 k 0ci8 e)lz,92K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kgnzzchcv * mi5 : w zt8f;gexzy-p447j4 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 insidsksj +zv,)cf (e the balloon, which,(skjc vfs)z + makes it less dense than the air 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 at 15ba(5a3o9 iwti:.cb nv $^{\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 atg1dr 80c/v- uui lw:jm 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 escapes a child’s hand at sea lxw f/:4vpu ; o+nm6css,c,-en k 4ptkmevel 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+9lu3rg- g .lt7a2w5ds rckvfo xy;y2scl3 y* / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many ml -9 7g)fhs37vwcbte eolecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number ob2viz/ bmdq5;p u(/di f (a) moles,    $ \times10^{22 }$ moles and (b) molecules of water in all the Earth’s oceans. Assume water covers 75% of the Earth to an average depth of 3 km. $\approx$    $ \times10^{46 }$ molecules

  A cubic box of volume vd0 5vhf(zjg 95.1$ \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 yo,(+ xrndy* po :wmadc+u inhale that were also wnad,+ o rymdc +*p(:xin the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic en2ftgj x8s4f)gergy of an oxygen molecule at STP?4g stf 8jfxg2)    $ \times10^{-21 }$ J
(b) What is the total translational kinetic energy of 2.0 mol of $O_2$ molecules at 20 $^{\circ} $ C?   $ \times10^{3 }$ J

  Calculate the rms speed of helium atoms near the surface of the Sun at a tempergpv8)qrx3 piu0o25n b .c7gxkature of about 6000gox8ickvq75 2p)ubrg.n p3x0 K.    m/s

  By what factor will the rms speed of gas mole qtiz55f )cc+j (jwx*ycules increase if the temperature is inci(ty)jzw c5qf5*+ cjxreased 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 havem;t+fm1ind 7)b c:j pb:6uwf3jwtmx 8 the following speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate thb6 np 3:fiwm1fdwtm8;c:x7 j) bm+jut e rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas ak ;2. k35nyt iyw1wpfo0dpo0v 6 ;sqtnt 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,mk5y7t)xh- uq by what factor doesm kh5qtuy7-) x $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given0 5-futx4ma1hkv,fcjginn*mv2 :j 4n by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture3/sre0c fx3fk of two gases at the same temperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecul0rxfk fs/33 cear masses.

  What is the rms speed of nitrogb ijtuj c)hj/;)f p8;/vipq/den 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 a7o0qi: utkj9an oxygen molecule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance between nitrz.5l2ksw6 /k wetla x*ogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 q: y.ztqe2p(:qvx z m/u in a livinqv2m q/ze. yx(qz::tpg 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 P = / +w9dttvqzl76rc pi-tkt *l1 $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uraniumwd;go cz0l:x t 9-jy.k8f3ore, $^{235}$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 wqbtqvh39qm h 6 ye8h2b2a/h.uhat 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 pre: vol 4/jfbx sx;yj9,t qxa,l-ssure is 0.01 atm and the temperature is (a)l;,a/o4v t, jjx bsy -x:x9fql 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximatmyp x5dx0 14+jh1 3p 8fdwmglgely) if the humidity is 50% on a day when the tempdp1xgd xpjfwl5m40m+ y 31g8 herature is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place whe8 wu5h)rs5a ucre water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place ina1snh:ha7)v b the mountains is 0.72 atm, estimate the temperature )7a nh1vbhas: at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of wf lh*igvtg g9 i0 e(y0r.s+ euadjm482ater is 530 Pa and the relative hu .yea0euh*rt2f v 0(d 8ggi4i+ sg9jlmmidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial ph r(mx18*nl emvz5tgl 30i 6tvressure of water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a : d-m x cjcau:q3 7mo6m1saw(t rkzs.6pressure cooker if the water is boiling at a temperaqdo3s .z-uska(16 c7 xr::ct mm 6jwmature 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 volume 680 0a25yj5d6q.xk p:ljwbk p a.k$m^3$ 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 2i 87s:dc3cf 94 bdjgyim0mkq 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 dixdy pdn3nc176ffuse a distan3n px1c 6n7dydce of 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 tubeo;vqk5foofztsp,9 - uxn3v2 7s called tracheae. An average trachea is about-7t3ofkoo,5;nvv x9zsuqf p2 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 8da+7njn)mvt:m s, -qkgsfe2been 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 has been calib7 mxsw 2kzye3 u6e;e3iww2;e rrated 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 calxa-q:+ gxv sq (*azkc;ibrated at normal room temperature. How much error will be made in a rec kaq+azq:x( gx-cv ;*sipe 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 initially 28 atm. After ma rgh4 gkhw/5bx*65q gsny ballowqg5*b46x gskg5h/rh ons 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 fe*q+trqm5x0di1c;(i lc- ch air molecules in a room of length 6.5 m, width 3.1 m, and -+*c 5fdt01 ;rcqxqh i(imeclheight 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 is about q )m 8f ;5ub.r-ka1xh:tyjbu1n0kuk qone 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 zlt9o91*vrwd bd j.+jthe best available vacuum techniques is abor1j+9.lzbv 9td wj od*ut $10^{-12} N/m^2$ 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 Lyq3,x0vm-5p*q vn dl i when 10 m below the surface, to what volume would his lungs expand if he v,qlm3id*n0x yvp q5-quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphezxlbzl9f6i 1 5ie :ke-re at a speed of about 40,000 km/h1 ez6ex 5bfiz9lkl -:i Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increased from 110 ;pe sgr 5(xh:hrl/;upzb76gw $^{\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 t3j,v1tym in($^2$ (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 ojg /-b0ig0/ tk d4bfqef atmospheric pressure at the surface of the Earth, estimate the total g /if0k04tj- /db gbeqnumber of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained in ao;ex wx 132 :,vhoo(tps-odi g 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of(/ 5wwia35ilv2v(msnu2nescn9bd 1 a oxygen used in a hospital has gauge pressure = 2000 psi (13,85c/be2niv 2ai w unsw3(n5m(s 1va ld900 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bz llpt6sgp s hc7.y8(r8j8a0howl 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 gasoli . s6b 0/fiozwh; fa;2l)iu1iyyjocd)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 Ear:b:wv-ish lmlh;k)j 2 th’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 glid9we(-e2aenc/m w 8t ass 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 tkfbz3. l+k7ni e, bf;in the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully chargedrh8/ezsky2ecdt +5re67+xm w b 3z/ki , 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 2p6es-f/ f rotEarth 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 throw-a-m8 xin(bjl n vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are throb -i8 (jaxnlm-wn at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubble of air from a dept gfb,z.dn:2 gpfl+s1v h of 14.0 m in a lake. Assume the temperature is constant ap + dl:b.v,n gf2gs1fzt 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 the air on the follox-p+ i:bdf9n zwing two days: p-9 xb:+i fdzn
(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 densitpjb*:c6dyw f4y of iron at STP, and when it is a solid deep in the Earth where the temperature is 206:pbydj*4 cfw00$^{\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 shri/h)5p2n v lgo mc)dtio;*q4/xp fs8ow that, for an ideal gas at constant pressure, the coefficient of volume expansion is etpnp h irdf)*5sic /2xq)vogm/84lo ; qual 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 consta; xz8e vn73p; g0fcovmntly dehumidify their cellars to prevent rot and mildew. If the cezc7 fn;gp0v ;3vm ox8ellar 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