Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic tabla; dr.7dmc:gy e or Appendix g:7.a; yd rmcdB.

Name several properties of materials that couldwt6r5: b4 shwk be exploited to make a thermometsww5b4t: rh6 ker.

Which is larger, 1 C mznic;: 4j; 3u nt4:gccqvxk .$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system 1mk im/ec 50 p6n3kruuB, but B is not in thermal equilibrium with system C, what can you /erm10n5i 63k ukpucmsay about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip o0zpw- co ozdyh /t76o)f iron. When heated, the strip will bend. Which metal willtchyowd)zz6o7p/0 o- 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 ox: ovlqi6n96;omqx(l. rpv:fgz), pmf linear expansion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple thermostat used qir r:z/ gbg(9to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different met rgiz:b/(rqg9als 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 h*keq)z+s h)a oq9uz,kave a section in the shape of a U.kqsz ,k )+zou 9q*)hae Why?

A flat, uniform cylinder of lead floats in md.e am0.zx*+mzz .nrl ercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is first placed i,sa 1mo- r0bprn a hot tub of water, the mercury initially descends a bit and thro - mprb,0as1en rises. Explain.

A glass container may bv5 fc0i-d:j l:(r gyenreak if one part of it is heated or cooled more rapidly than adjacent parts. Explad iy-:5fe0:l(n vr jgcin.

The principal virtue of Pyrex glass is that its coefficient x0o o/conmz qvr13/cgl0 3uo 1of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increase0xv og1 1cmq/co3roonz0l/ u 3d heat resistance of Pyrex.

Will a grandfather clock, accurate afd/y*2 klg n2vt 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 itsy;tkd 48 syw.y bottom and top to bulge so badly the can will not s48 d.wy;tsyyk tand up. What has happened?

When a gas is rapidly coxjn)s5rna .z8mpressed (say, by pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. E) 8ajs.5nnxrzxplain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an ald d/w s a3va2v/z.5qcluminum sphere submerged in water increase or decrease if the temperz/5.vddvc/ a3lwaq2 s ature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theorcwg+y1a.ymxmdl: f7mw /..t7hg ,/l u ki+ hauy and the relation between average kinetic energy and the absolute tea.cmk+h ,yu+h7. w.wy/ug mia:l1gx 7mdt/lf mperature.

Explain in words how Gay-Lussac’s law follows from kinetic h3b7lo7a+j ;:s lee c dt3edy,dy0cp*theory.

As you go higher in the E8t dbtc :(fqo/arth’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers t,tkkv:k *y:kao the minimum speed an object must have to leave the Earth and never return. The escape velocity for the ,*kkt:a k:v ykMoon 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 tem hmg5:t;(jp-2.lm uk tqnn n1iperature. What can you infer about the molecular properties of one re 5 ;m-(q uhm:n.2lpt1nt jgknilative to the other?

Explain why a hot humid day is far more uncomfortable than a hot dry day at4wgu4f/qwcln 3y)0y+o/ nm pt the same temperaturmo f /uc)gwl3n pwt4qy/y04n+e.

Is it possible to boil water at room temperature x j)rov 0+jg.wdwc+.cwh- rw5 zif+9h (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperatur*.z+sl a1 ftms-egq* qe is the same but the humidity is different. Wha *lqzssgm+e q f*-.1tich is more dense, 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 a43pvj p662n1mixc xjsutomobile engine.j2 xp nxc1jsvp4 m663i

Why does exhaled air appear as a little white clouddpb1 xlv-hr+jvwky scw:vari4 17 :6s2ux7y/ in the winter (Fig. 13–28)?

  How many atoms are there ini+c 8wmpwq s;0 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 in atd9rq,8j e fg /*ldu1um)ux hdqh i:30 silver ringxh0, f9qrhq/jei d:u3t*lu8 1gd)dum of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is ofte 0fgc/( ccy)lnn taken to be 68°F. What is this on the Celsius scale?(ncclc)gf 0/y    $^{\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 1ex3 +8 phxgop6vgz9jcmh5 y1recorded 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 td 8-pdbbi)okz5u5dk 4hermometer, the alcohol column has length 11.82 cm at 0.i8 uk5o45d-)zbkdpdb0 $^{\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 slabs 12 m :so-.staxg+ 6rrcv 5/ qd uo0vlong (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 iron approximat*n2-gc d 5zr7doqrg:g :aa a3iely 300 m tall. Estimate how mu :d:*gdaa 23crz 7oq5gira gn-ch 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 rivet h8dlf401qq*wyq o ,m pnole are often used and the rivet is cooled (usually in pq0ol4m d*1qf y qwn8,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 $^{\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 4uu0ai5t .drk $^{\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 volume4q e le 7ying6r0kc*6l if it is heated from 307ie4ec6 lyl0qg6nk *r $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled t**noeqkp 6f;fwvdeb52j)nv n-qvj *,o the brim with 350.0 mL of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL of water irg/z6g/9 zjwgrm ,jb6xv59+s jfd3 a 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 plac;4j iwawx) qg jjp;rli:jm xj; 5en032ed 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 exp c2b8pyz3o7j+cl j.t )c*6noom5jzdj and in essentially one direction oc 8c6o njbjd*zj5)to m2l .7zpjco3+y nly, show that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in.t1mzpadrh ( *b)s: ep the density $\rho$ of a substance, when the temperature changes by $\Delta$T is given by $\rho$ = -$\beta$$\rho$$\Delta$T
(b) What is the fractional change in density of a lead sphere whose temperature decreases from 25 $^{\circ} $ C to -40 $^{\circ} $ C？

A uniform rectangular plate of length l and*dyd xhx o4wg6;.,xz(x.rhr wdr)t p+ width w has coefficient of linear exrw xhtd)y w.6 d*o+;x.x(4gpzxrrd,h pansion $\alpha$ 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 solidyq bp 4x:4-mqvu :ir8u, $\beta$ = 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 mpbznr czk7nh/+f7 g8/ti /.caade of brass and keeps perfect time at 17p8nz 7.7hzi /kac+r g/bcn/ft $^{\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 thermor 10ay. 2x26q6gqjl sfq v)egbc hj:p.meter has an inside diameter of 0.140 mm. The bulb has a vol a2sejv 6ly c)g.rb21f .qjq6xhg:pq0ume 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 i 4 r93znduz5mks rotating about its axle on frictionless bezud5 kmn4 3z9rarings 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 15°C. How much stress lov*5to *jz3f 8/idd dis required to keep it at t/ ovjl*odz3td f*8d i5his length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional am7qp./p ykmc9uiv *7 prea 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 a l4alg5+:tj swt 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 Kelviny7taknv*uz8 9 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 temydi0 u h:,tj,tperature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are about u ;+ u7 ne19;ptbxkrmc4000$^{\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 pre8c8jql4h+ vct37g b5fjg ta0wssure and a temperature g4cgbjh8c8w l tat05j7fvq3 +of about 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 g0/fw ,vpkcfnm98k: umas law.    kg/$m^3$

  A storage tank contai-liypus qf48 9ns 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 STPgcwx7at-m p/5u x x4ka8f9/lya;o5np contains 18.5 kg 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 at 10.0o6dxu m fkgb *0porn*96 yf+j($^{\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. (ycardc a)d1 of argon gas at rc(c1da ay .d)385 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg-)qebp ej f,woy( )t*g 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 achzx2+r d n;bkav /it89kieves its buoyant lift by heating the air inside the balloon, which makes it less dense than the air outside. Sup; +r x2it/zkdv ka8nb9pose 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 airfn z29*yc85 ej 71 sqvk*edtwo 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 am,aret/ e.l am0o0bxy* )gcy 1t 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 level and tz8yjnfcr -j(fl)r /;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 or0 0mlzg(l1vn oc8 dzk- xa)o1f molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L?8pvf 8jub (+ 587g/ +wk+jk8buwpdgufvg p :hq How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) mole6qj)9 b jqlwqj z5o1,cs,    $ \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 5.1,zfbe/ ru8h7m a6 vy:y$ \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 h t4d3yy ;zx5zeach 2.0-L breath you inhale that were ad;zyh4zt 5yx3lso in 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 energy ofqu 2xpx8ft 2/x ste:t7wr,g k2 an oxygen molecule at STP?t2qwtr8t ek 22psxg/ f :xu7x,    $ \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 helpd3rn hpy27 qjzq:u2nh;6 d+mium atoms near the surface of the Sun at a temperature of about 6000 pj3n q urq+zdydm6p;2:27 nhhK.    m/s

  By what factor will the rms speed of gas molecules increase if thzte68qn4 0fo ne temperature is increased from 0f zne4q60not8 $^{\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:ptlcj-o 2,us0+d b+gd 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8.++lo,ctju-b spg 02dd Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gaw 6vjzaf6-*x1p hu7kx s 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 volu5 z:,l aolbfia: 0 sg0b7zv*rfme is held constant, by what factor0 i5r7*zaso : blzfbfg,al: v0 does $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is isa5h6 4+z18 umrt/ym8jegt zj.s5d sgiven 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 gast.ebfxjv *0*(wi,xc ces at the same temperature, the ratio of their rmce0*tvj.xcf*i , (x bws speeds is equal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrog8nw(fxfn n* ldr7-9yken 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 9np 46/ sw,,*ysneq yvuvrq1van 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 nitn 0e1.sx0fkhypy*ex9rogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecularcdb75g)f7xsn1 z1c dr mass is 89 u in a living cellc 1g xbsz rd7c5d)1f7n 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 =uy6rg;.ur5 ii4zu/ s r $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uraniumj(.*salw e qe; 8mf5rv, $^{235}$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 a ob.d0j*ell//ckbu20l jna7uy0ub3 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 presap53a 3ix-b ta:x w5wu3gj.r qsure is 0.01 atm and the temperature is (a) 905i 5twqba3 puwr:x.x3 -jga3a $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on aml y u5 ,ej9cq5yy*t98fzyb;g day when the temperature ism9,zgutby5 y*85ec yy qf9l j; 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boils at awz q, prrnd-h .zc.3i8mz4lf5xvv8090 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a para,3,kzb mn hl.ticular place in the mountains is 0.72 atm, estimate the tempel3an,zhm k.b ,rature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of 1bv erfnzq7vu5gufb/ +p l, ;hca6.e *water is 530 Pa and the relatiz, 1hprq+n5bae7fuvvl;*6 c geu/.b fve humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure x.y*;h9u;pb0tg scmf of water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate preffdfm89hf*v+d2 v8po1wt c b .ssure inside a pressure cooker if the water is boiling atobw+vmft*d 8phf.89c 1f2 dfv a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of volume 680b: oha8 wp t oz:u81s6hv)epr7$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dew po, )ssqrbi.xc*; p4 zjrint 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 (see Table 13–4) to difful7e5jvhg ; 4.e mn7hovse a distanceegj7 vh4h n.;l 7m5voe 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 sffpozi5 cv ;a0/7 3ypoq8cb)k urface of insects to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has ckfcbvazoyp 50f p 873;/)iqocross-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 ca7rco7:wu xv)fh .vu j( +rsw(vlibrated 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 calibrat b;j17( ouu;qqvn1 nia*8yst ked 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 .myw ;pvftnt)z3r1co zn( *wbd +cr/(error will be made in a recipe calling for 300 mL of cool water, if the water and the cup are hopo ) vt wc rzt.n(nw;dy/*zb1(3mf+rct, 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 initng2qg.puz8za9;1my 0j d+ z fmially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 zafju ; gmqpzz0m n2dg8y .9+1atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules i3z cjx7 upe2 ,(mk3bpx0au 6pyn a room of length 6.5 m, width 3.1 m, and height 2.5 m. Assum3c xy3 xe,u2bam 6zj(pkup7 0pe 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 abouti)iivoq-o m7 (h)ur yj /tc3*w one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable q8u v8ygzegy d31n3tqx1l; 09u jgf a1using the best available vacuum techniques is aboutd l g81ey;xn39 ay t18g0 jqvzu1uqf3g $10^{-12} N/m^2$ 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 h0 2.(8wpnwekzv wr*iq*e f e*pis lungs to full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he quickly ros2wf*zee0(r8p npq i* .kew*wv e to the surface? Is this advisable?    L

  A space vehicle returning from the Moon ente: m;hdma*h+j prs Earth’s atmosphere at a speed of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a m;h+dm jha *:pbright blaze upon reentry.)    K

  The temperature of an ideal gas is increased from cn,fp :vip.ur(7s()d*n6 m5c xsph jd wt:rl,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 ofif c10wjtff6. 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 at the surfkvs7; -7mqn myace of the Earth, estimate the total number of air molecules in the Earth’s a7s7qyn; -mkvmtmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules conts:6b 84c :qutkad rkpnj/4j- uained 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 gaugej:wt,o3qbd6 np 9o(mu*fy 9de pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.nj(9u6f,y o9oe p:m*qd3btw d4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquidj:, c zuhluv18 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 gasolin9hzb:y3,aio fdm.nongy:)i (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 fit snugly around the Earth’s e8dii uwr v,80yquator 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 l-2z* 12esafy:,z7d aivrukjonto 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, adk)9i -ja; n2fcgy2zx3cxcwcq).z ob * opted 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 charged, hszmfaf4*d8hu n.s;(vk0 f w tlm91: anas 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 fromhb:sx1e gw* 7n-2tnf f the Earth is $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennqjy vd+ot 0d8w2ory;*is balls thrown vertically upward+vy ;*roj0qt d dy82wo 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 thrown at 12m/s   balls/s

  A scuba diver releases a ap:vb 02jo3hfvl ib/23.00-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when ioh:p 2af 3v/bl0ijv2 bt reaches the surface?    cm

  Calculate the total water vapor pressure in the+e2 7ivqlc(1qnmqm7x 6y wz 1r air on the following two days: zq n1eym7l(2mw6+vcrxq1qi 7
(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 /w9v+hoe3 q.yo*1 nkxdpw4q8 8 z*ghanx(nfgSTP, and when it is a solid dho9v8gf/*n+4x *(y g qna1n3qokzeh. 8pxd wweep in the Earth where the temperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show2qp qgeir3/53fn*dxy) zme )y that, for an ideal gas at constant pressure, the coefficient of volume expansion is equal 5*ig p)xe mq3 /enf2yd) rqz3yto $\beta$ = 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 coua:yv1dsa l e/d* 5wa5nstantly dehumidify their cellars to prevent rot and mildew. If l1wv/*5:adsa 5d u eaythe 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