Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic t;37 l+avarqid7 cojr 2uc8g m4able or Appendix Bjac+r ml 737g uarvq2;4o cd8i.

Name several properties of mjdyu *f9d56 ;,m44opec pdkur aterials that could be exploited to make a thermometerf6,4e dy upcm5;k4dpjd9ou * r.

Which is larger, 1 Cu (;gcs1j/t pu $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B isdpq pm y9b:mq;4w10 yc not in thermal equilibrium with system C, what can you say a:w9 y1pyqq40dcmp;mb bout the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. Whenq8:zm 0hwz7s r8*wxdy heated, the strip will bend. Which metal will be on the outside of th 8hsxr *w yw0z8:zqmd7e 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 conb,gqc ,b; 6wh2md*ung/4 ,y litq ld)ar+t p*efficient of linear expansion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple thermostat used to zr/lbd dqsil6 b-0 76h 9jg hhmu:-sv9control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that/l9b s q9u0hvh -7d:gb6dhs- rljz mi6 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 p): qd/1 nsss4tk r1;9zbobvh a U. Why9 zt 4bqds )bvn 1r/oph1s:s;k?

A flat, uniform cylinder of lead floats itaa3 +idmi*1h:c zlyqgz4ps 24o jd /1n mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is first mh7+/wsd8iul wf/ gb* placed in a hot tub of water, the mercury initially descends a bit and then rises. Esflbduwh/ m/8wi* 7+gxplain.

A glass container may break if one part of it is)07s9jmqp9e + xyfn u hgek5z4a 0kcq2 heated or cooled more rapidly than cgk0m +uq f2h5ax)ee994 znqkspy 0 j7adjacent parts. Explain.

The principal virtue of Pyrex glass is that its coefficient of linear expanr2*,i3dw nw+.hn .dwftwv-f msion is much smaller than that for ordinary glass +.w d.rif v*wwndt,f3mh2-wn (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather cloc1nkl1nfjh .+ek, accurate at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and top t.k2s+7wmbgri3qsp4 5oua nt1 o bulge so badly the can will not stand up. What hasqarigs +s4 p7u1 o2wk tbm3n.5 happened?

When a gas is rapidly compressed (say, by pushing t/hhbf t-.vpqikz+k piy 0e 2:-u*b8jdown a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what hap q.bhyku0b piki8 -h-t t*+:/p2vzefjpens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on any 9onx8kaw4 3y aluminum sphere submerged in water increase or decrease 9n ko3axw4y8 yif the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theor2:9q h ynpf+izy and the relation between average kinetic energy and the absoluteih:n+2q9y pzf temperature.

Explain in words how ur- (mxy1xom2a*erd: Gay-Lussac’s law follows from kinetic theory.

As you go higher in the Eafz 3izkeap; z6c v7cv*:dth-t 17xd/irth’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the9d9yr c g0b(x ae6six. minimum speed an object must have to leave the Earth and never return. The escape velocity for the Moodycxg6r.0 s ( ib9a9exn is about one-fifth what it is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What /w 8iojfov*0y 3td2jjcan you infer about the molecular properties of one relative ioj*t jfjo0d28wv3/yto the other?

Explain why a hot humid day is far more uncomfortable than a hot dry day atcgz;oj8kykggf2bdlu* /f9 uu47a 21a *r nj.g the same temperat8jz;ya2dc kggu k* ub/947r.*joglg ff12nuaure.

Is it possible to boil water at room temperat( ss h 2yjn35zc ap+vd,xh+ax+ure (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when t8 5xfe.9r4cvbb qi i-the air temperature is the same but the humidity is different. Which is more densebci qtb -fe.45r8x vi9, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to op/. 3 ejzidratkx;.(rten the radiator cap of an overheated automobile engine.dt.rjrx;e(azi/3k t .

Why does exhaled air appear as a little white cloud incdos u0gtw9/u 2a,jn 0 the winter (Fig. 13–28)?

  How many atoms are there in a 3.9w6yxu/- yu /ggfv;bf4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to thej2xhjd; 4r6l35nin q h number in a silver ring ohjil4635; n rxhndq j2f the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken tq u..z6q d5g yhed.xj0aay:h5 o be 68°F. What is this on the Celsius scale?d .yy.5qz:g .0 hdju6hq5eaxa   $^{\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 an v ;tjz5b/yv- qp8w5hzh;:vz pd lowest temperatures recorded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

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

  In an alcohol-in-glass thermometkma-5a: ua z+ter, the alcohol column has length 11.82 cm at 0.ua5m+-z :ak ta0 $^{\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 butm*eib; p0-mfilt 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 (Fig1 rs4govfd( 2w. 13–29) is built of wrought iron approximately 300 m tall. Estimate how much its hedor(21 sw vg4fight 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 x3h)bsthf6 v, larger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet,hh)x bvt3 6sf 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 jhrwom . f x8cw6lza433pm9:*icuc- xat 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 u/or9 lle: a-bl 2)ydxx1/fa nwill be its change in volume if it is heated from 29 a)u/nxl y/: o1llxderf- ab30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL of mwt kzoa.(6z4:xxky/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;gg/(o5k-x:fdr w6dv t)cvj 9eh6jzp 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 in a ring madh7ddut b9:+xy e 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 contain/ lsas+ cw0)9pz llk4j;ala, eed in a long, narrow vessel so it can expand in essentially one direction only, show th;9esl+ lsl c,wk/4zlpaa)a 0jat the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in t )t(et37yuff. hhi l-eq/b5wm he 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 width w has coefficient of lineaj8xtly*)qsjp*:1 wbpr expa* : j)*xl s1tj8wbypqpnsion $\alpha$ 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 isotr(uq-30yt ui*9xboihd opic 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 clock is made of brass anrtd25 ok/l gkbxikmp);7e -/s d keeps perfect time at 17ir k72k/5ps/golbd te;kx) m- $^{\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 mercuy -,dkls47 ;pxlxm5ibry thermometer has an inside diameter of 0.140 mm. The bulb has -slid4xmp ylx, bk75; a volume of 0.255 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylindrical wheel o*rp:wgi6*tc nf radius 0.41 m is rotating about its axle**pcrwt ngi6: 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 desired length wd9tz2w d0fg, phen at 15°C. How much stress is required to keep it at this length if the tempera90dw 2 fdzgpt,ture increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of 7 u(fg,4qbsqncross-sectional area 0.041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 134gfvw a0wj:5r/q6v 2ab .122 cm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on the d(8g z:so fe)gKelvin 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 Fahrenheit scaza ho a+ gzfor7 9x.j.va*68ysle?    $^{\circ} $ F

  Typical temperatures in thrnl 105g 3hnfpfj+o9b e 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 ata/ 0pad6wwcq ( atmospheric pressure and a temperature of about 20 wp6a/0cw (dqa$^{\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 densitt*y7yop 8 xogf*yoywy:3j v 1ni) 6hf+y of oxygen at STP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitrogen o5 m0 1qsa)txy($N_2$) 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 STk fs/k9uc al39P 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 heliumm;z6buqpp7l 6 gas is 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 w3j-jnp6 a wi8105.0 kg of argon gas at 385 K?w63ia- 8 njjpw   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg ols:+i- mocy*t y .8x 4ctf+othf $O_2$ 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 heatingtnz7v3*w xz ;c the air inside the balloon, which makes it less dense that wz c7;*xn3zvn 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 y.-+eevzbw50 m 48uwvrfc nj4 air at 15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at 5ndzu,v1. fg hnujq8118.0 $^{\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 escapz o;1,9bn+ lp yru6ktaes 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 moleculesug kg62v 1+ree*yzo *o / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 j6f2y p6 pj*aw.ypep7o7 f9a -i7zqfaL? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number ochzklyj402 xa4 ejl00 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 volum fc+y7-qg,i54cer ail e 5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L breath you inhale that wtwhgb*+ 2 sp8here also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant t+2h shgw*8bp density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen molecule-,f n.vyug6s:th 5swx at STu gf-s:ywxv5n .6hts,P?    $ \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 t,-gm*9g)c hwptqdfm (emperaturh)-c9 f,mq*tdpg( mw ge of about 6000 K.    m/s

  By what factor will the rms speed of gac8fhi8j3w xy7s molecules increase if the temperature is increased from 08 xcw83jf h7iy $^{\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/vvghe jw(.;p. s: 6, 2, 4, 6, 0, 4, 1, 8, g(hpwj;v ..ev5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molr xbr138p)lkd u6b 4fvecules in a gas at 20.0 $^{\circ} $ C is to be increased by 1.0%. To what temperature must it be raised?    $^{\circ} $ C

  If the pressure of a gas is doubled while its v3j/i7gzof6 qg i cqb/8olume is held constant, by what factorg 7figz8qc/j oq/ i63b does $v_{rms}$ change?   

Show that the rms speed of molecules i;j ; ewq n)j/sz9w-rapn 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 at the same temperature, jm;gbwge0 / zkgv5jt;0g 2nl,nf46vqthe ratio of their rms speeds is equal to t;nn /gj0 fbwj4l0vezg mqtk g,62g;5 vhe inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrev )*r9 yr1x1hiu3 gpx+vn u vbwm46-yogen 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 5qc+ elj riu9 53;ytjvof an 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 nitrogen moltx/ws+o;8 oh9 q+x-pnw x4l bvecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acidius9i8fpjxax7 ;b5q- whose molecular mass is 89 u in a livinx;uq9fa 5 i8jsbip-7xg 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 pressuuksg(v +l123av q9mhqre P of a gas 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 urani *t+1c-wb stupum, $^{235}$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, i, e+bzss*m.1tmxuooa f;z)k8uo95g k n what phases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure is dbofln-*4qa*p +2jmvo 2yo 3 *y0bamb0.01 atm and the temperature is (a) 90 o 2obvdyl+2m*mopbq *4-fa03ja bny* $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximageewaqs2 - s,lh9fs*4tely) if the humidity is 50% on a day when the temperatu2-ges4le s9qfs,h* a wre is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure ax;8fkq; )o4 *4 hw xmg*tkcs ntgtj*r+ k/ih,tt a place where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0su /v k9tz1l2wmu90r m.72 atm, estimate the temperatureluu kt/mz20 1vrms9 w9 at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature 58run7j (njup on a day when the partial pressure of water is 530 Pa and the relative hujpun85ru 7 j(nmidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of w5x2su p()gx(kjbajo /ater on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water is boilqggrz n/ /;waqk85sf 1ing ngz8wk1; srfa qg5//qat 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 rpm5n+nbk4* ) r;h ryzfoom of volume 680$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dew point of k k8)w8gl937 yldfikd5 $^{\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 m tdevyocx h:na82t 62+olecule (see Table 13–4) to diffuse a distance of a2v826+nx yheotctd :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 theidcgza t/u3-,be7 gpm028esp surface of insects to the interior through tiny tubes called tracheae. An average trachea is about 2 mmc , b/2 3em-spdp80ag7 zgetiu long and has cross-sectional area of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been calibra a5 vey(4g l;,uinrc4b-glws88q6gjn 5k:yprted 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 meal,lh *zmsd6ux8m n x(mt fs4-*sure has been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal rm9.zm ie, 6x k81baiaycj l6u-oim86joom temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water and the cup are hot, at-mc 1az,e 8 kijai6jbi9lo6m8.my6x u 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a heliz, c+l +:vfa8;jernl vum gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What,8+a+ f;:cl rzvejn lv fraction of the original gas remains in the cylinder?   

  Estimate the number o jzgf apbfoqsmb1.* l7)28zb+ f air molecules in a room of length 6.5 m, width 3.1 m, and height 2.5 m. Ass8 a.jqbm)zpf *lzb+o sb217fgume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density ofhhb (w-tn*) p r;qu;dh-x4uob matter is about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best available vacuum techniques is ap z,he )c0d/bfboupc)h/,bdez f0 t $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fills his lungs to full capacity of 5.5 L when 10 m below tfm u:cl* inxl84(pik-hj62ci+jj l, uhe surface, to what volume would his lungs expan6c ji(lpx*knlhi 2c,j:- 4u8fuj m li+d if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’sz4jg fz +m* j88h*pcdk 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; inzm*4c8 +hjg*p f8zk jddeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an idy(d vi2u yifh;efdh(( j8*fon.q m(is*4xe8peal gas is increased from 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 p6vw -xn:jeks1 a5hio:q y+3;e*nxayof 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 surface of th9 ze e83oycof0l1rn 5-lrjl-e:p ye-y e Earth, estimate the total number of yy-ny5 j1ze -9 re0or ec 3ofll8ep:l-air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules containw-h/-c hxk- adp+1lkmed 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 hat))kv,1b6 (7q6tac pf anpgars gauge pressure = 2000 psi (13,800 kPa) and at T = 259K H7t6b g)rn pf(,t6pcka)qaa1 v ow 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 bowl o;9 8+byfxgl yvf 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 gasolio9w.zu;./dm:ftc) v t; mje cdne 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 fn6zdz)qp4 ff8n3 u(wtit snugly around the Earth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws ti z 2:etdv7a*, nd7rmcyghtly onto a glass jar at 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length standard, adopted in thd.20xvkz jxb0ffaj;i /o1pam s 1v3.ne 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 charvhgtuqtwk/k :s - -b18t b77tvged, 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 Eat6m vg806vzwob gl(3 frth 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 t) ergvgh7zor- u0 4h:by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a vz0t4: orr)h -ug7gehmass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubbl 0) wcy3trp;sesh j5z4e of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, a z csjyph;34est0 5r)wnd 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 following two dayjaxi a d .a)-0nv)nq /lmzwv2(s: x vaq dn.2vl)za(wn-) ija0 m/
(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 dp .yzb1 *;k-.box;lmn3 vjrpdifference in the density of iron at STP, and when it is a solid deep in the Earth where the tl . n ;ybrjvz1od*pmkx.p-3b; emperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, for ad 4dst0t ygx9bij b9:(n ideal gas at constant pressure, the coefficient of volume exgt xd49 i:bydj9(0tbspansion 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, peoplee4m6 ss) w-6uvjcmfbp p3y(n4 constantly dehumidify their cellars to prevent rot and mildew. If the cellar in4s34 j f(vpn-pmmuw6sce)y6b 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