Which has more atoms: 1 kg of iron or 1 kg of alumiv3 xy,jjq h33wxig*k1k -g/alnum? See the periodic table or 3x/jwlkxg 3v-qaj3*hg,iy k 1Appendix B.

Name several properties of materials that coulcy;fut0w l ):rd be exploited to make a thermomete) :ulrwf0c ;tyr.

Which is larger, 1 C khh:vf+a uv1 *$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermtjua19 lj;mxf.m -z l7al equilibrium with system B, but B is not in thermal equilibrium with system C, wh f.mjt9u;zll1 jx-7ma at can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a stridc-zri5 0 ttdilcb,i)f:/a 1vp of iron. When heated, the strip will bend. Which metal will be on th )da/ dl,tcfc5 01:-ibvtrizi e 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 exc2qqtd y1,- jxpansion $\alpha$ 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 di3i;j2.p8rkwwl1zq rk g (pr,dagram of a simple thermostat used to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how i2,pwpdj1rk (3 wlqr.gk;rz8 i t can be set at different temperatures.

Long steam pipes that are fixed at h- rn)7pe2kuw3 8,gmhg h b-tuthe ends often have a section in the shape of a U.73,rbu 8whe) mnh-t2g gk-phu Why?

A flat, uniform cylinder of lead floats in mercury at 0 8,o r: htiokd6b.c jg5cxb n5($^{\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 in a hotat*+6o/xo30k4 p xqkem7u-nt5hwy;mvg2 b qm tub of water, the mercury initially descends a bit and then rpq;kt* v4n6g htyx uo o3 5kebw xq72mm+0m-a/ises. Explain.

A glass container may break if one part of it is heated or cooled moc3k( fi7ucrk: re rapidly than ac 7f3ck u(kir:djacent parts. Explain.

The principal virtue of Pyrex glas f kw6mnfvk yi :-24rgk91+o c-powla0s is that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increasl:kfypk -wvw4rkon6coa +1-gi0 f2 m9ed heat resistance of Pyrex.

Will a grandfather clock, acc jro)vx/m v er1 xdtijal(5- 5ml0,af-urate 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 botto hyd-k.zk9)v6 -i5ctn .vx agom and top to bulge so badly the can will not stand up.y o.5ta.)i - zvxkg96vdkch -n What has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its temperaturhka wazh 89;nfk*3p uk461-r7wke nm2d2ncr ie 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 wh1n; n - krwn h2 8kafrkpa79ie3umwc*264kdzhen they strike the moving piston.

Will the buoyant force on an aluminum sphere subme n s6*5lux4h+i3t qydcrged in water increase or decrease if the temperature is increhx+ ui5 tys634*qc dnlased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and ther8ynap7oe9 d0 -xg(o55rvk pgo2c jo* relation between average kinetic energy and ynx5j -9gd 7(0ko*5 rcpev o rapg2oo8the absolute temperature.

Explain in words how Gay-Lussac’s law follows fro wc9xxgap:0 u *km)egaz 2-0dcm kinetic theory.

As you go higher in the Earth’s atmospher1clrl8,kf qo+e, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object mu8+fja8h 13xd4w hvrfd 8x1v zrst 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 Moon has prac8 8xj3xadr81v1 h h 4fzwrfdv+tically no atmosphere.

Alcohol evaporates more quickly than.1x)m pyx7kde water at room temperature. What can you infer )mky7xxp d1e .about the molecular properties of one relative to the other?

Explain why a hot humid da6c zh4p)x6dzay is far more uncomfortable than a hot dry day at the same temperatz 4ac z6hxpd)6ure.

Is it possible to boil water at room temperatursrdid,9 56ami e (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is thtzmpf+;cjq pbsl 32qnd;o:jwh+8 0s,s/yz4je same but the humidity is different. Which is more dense, the dry air or the humid air at the same T? Expwltz8q d2; sf4;j/j0 p3mhp,y:no+ z bscqs+jlain.

Explain why it is dangerous to 4qsbve-892d. g zgvxx open the radiator cap of an overheated automobile24.vzxg8 egx-bsdq9 v engine.

Why does exhaled air appear as a little white cloud in the winter (Fig. 1 wc:6jhw8vpd 53–28)?

  How many atoms are there in m79 ud*2qwc n+x +vjpna 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atom1 pl.cbfo d+l+s in a 26.5-gram gold ring compare to the number in a silpdc +f bl.l+1over ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken tz+qng y 0nx ,2gl-gdl.h,xe6eo be 68°F. What is this on the Celsius scale?nl,xg y+6xe0h q gzgn., del2-   $^{\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 recox5lh)m t.0s twrded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

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

  In an alcohol-in-glass thermometer, the alcohol column has leehzi,rt,xo1fe14 ht3x j*g2 l ngth 11.82 cm at 0.fxiel,et g zh 4hro2x ,jt31*10 $^{\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 long (20qb.zje n c;aylgbc8z 2 41nu)i(5e3xe $^{\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 approximatel c0f+ jgi7bljoa9;7xsy 300 m tall. Estimate how much its height changes between July (average temperature of g7+oi;jbj9xsf c 7a0l 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 often used v* qy2u+, yvl :imteu*and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm m* t vvquyeilyu: ,2*+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 o t+x)fi +kha2at 4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be itj(hu: ukj6j bd1yc.s2 s change in volume if it is heated frhb:su(d j y j6kuc12.jom 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the b qho..w6htf-oeyf4rl 0h/( ilrim 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 at 2a7.j,rz; d2fdv.rim *ry) stv0 $^{\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 ma a.lzk shmd.w9s.1:n ade 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 expd 4fsmz v(327fp:w/jzeql .e hand in essentially one direction only, show that the effective coefficient of linear expansion is approximately equal wp2l e h/vffdm4 e (z3:z.jsq7to the coefficient of volume expansion $\beta$.

(a) Show that the change in thko9h 8anibwe1i* 2 vp1e 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 le 7 l-zj79htab,7 c ekc3:pkq)x+f bkczngth l and width w has coefficient of linear exp7 ba h p,kb e:cflc)k+q3zkt-79z 7xjcansion $\alpha$ 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 sonzu98j0r z/ckq: a2v*ciyp, ulid, $\beta$ = 3$\alpha$ if the amount of expansion is small. $\beta$ and $\alpha$ are the coefficients of volume and linear expansion, respectively. [Hint: Consider a cubical solid, and neglect very small quantities. See also Problem 18 and Fig. 13–30.]

  The pendulum in a grandfather clock is made of brass and keeps pe;+e a46c, lot4 hzwsb+wnk )sirfect time at 1744lwoesw+ct b i, 6sah)n+z;k $^{\circ} $ C. How much time is gained or lost in a year if the clock is kept at 25 $^{\circ} $ C? (Assume the frequency dependence on length for a simple pendulum applies.)$\approx$    min(Round to the nearest integer)

  (a) The tube of a mercury thermometer has an inside diam gb:v -c:1ui8nr4dqh zeter of 0.140 mm. The bulb has a volume ofng 4d:8bzv 1qci: uhr- 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 0.416q/ufxcuf.c8 m gbr 3y;i-au+ m is rotating about its axle on frictionless bearings with ac-mur+xf6. 8qgfai/;ycuu b 3ngular 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 tzqkepah:x +k b3o+n i*ao-,)jhe desired length when at 15°C. How much stress is required to keep it at this length i qx3+-kj bzo,kp ano:a+)hie *f the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional area 0beg* /f,qy;b;;:el 0xvhhil r .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 ate1;9m nygcwa r7lau88 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 temperatu m 8xjm;wvc*5hres 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 temperaturww e z -u/ylevl2x9,9ne on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of tq ;f7u7 uai3mjhe 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 press8rpus3wqfxb1q n2y+ * ure and a temperature of about 203yuq pf +r s2w8nb1*qx$^{\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 gtt;taml8jo8 0 as law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitr.. ,xrq ud.fdlv3vf1 jogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.5 kg of nittufg.n sz3*w v;vl g.1nv jx7(rogen ($N_2$)
(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 10.3,hdk-jio:0 mipdlgw, )w 2ag 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 ghvojlnu.0u68jo9v o+hsn9 0e 6ps+tholding 105.0 kg of argon gas at 39nu 8nvho+joo6ls6 v+ju00s9 t.g phe85 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 nxu1fj 0 torab;3iq- *kg of $O_2$ gas at a gauge pressure of 8.70 atm. If the oxygen is replaced by helium, how many kilograms of the latter will be needed to produce a gauge pressure of 7.00 atm?    kg He

  A hot-air balloon achieves its buoyant lift by heating the air invt9* c zatd+2fside the balloon, which makes it less dense than the air outsidt z+ac9fd* v2te. 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/bi g je 8vl2pmfa-p+, 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 18.0i mgytgriqeo;+ic(58eu,.*f - *f (yac2pzgw $^{\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 leve7 .k6e 1cqrhbdl 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 o3 ): ygi.fsqvhf molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of wa wx 6ur-v.4ekvp(j aa j974fjqter are there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) m*f2dg4 c (emm)git0sxup 2jx (oles,    $ \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 57t a+ z6sv 4zi;l, iicbfbpo.6.1$ \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 th z5c+sp x.q.q0umheq*at were also in the last breath Galileo took. [Hint: Assume the atmosphere is euxc *m.qsqphz. q50+ about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen molecj18ppkx.0y1t wgm6l ;t5nrc0;kx z z gule at STP?pg z;ypk xg cr.k10; lwzx8tjt51m6n0    $ \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 ox- g6k87kabri.l. t/ t kbt/uaf helium atoms near the surface of the Sun at a temperature of ak t rau/it-gbt6/l8kk7a.bx.bout 6000 K.    m/s

  By what factor will the rms speenw6b. ry h2i9ed of gas molecules increase if the temperature is ini 2b6ew.yrn9hcreased from 0 $^{\circ} $ C to 100 $^{\circ} $ C?   

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

  Twelve molecules have the following speeds, given in units3 :ttu6bz4 pef of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8.3t :tezbuf4p 6 Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in ax6y( 63rmvgindwm*+n 8 *1 .ah*oijhl1deuw 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 volume is helobqfbc3*t.faas ;s; -d constant, by what factor ;.s fta-*bbfq3soc a;does $v_{rms}$ change?   

Show that the rms speed of molecules in ayiw t gv(i26vw(5 q1+u e,dbpb 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 two1zm60ql7sn me j,i0rg gases at the same temperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecuzn lq0s7gjme6 i0r m,1lar masses.

  What is the rms speed of nitrogen molecules contained ie-m/c6;wpm(xcjb*h r zha66+ksmx g)n 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 ofb8xav,/p / m tg(0vefas*h s,g :wlbw; 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 molecuvwt p,mw9.cu v4jg (z4les at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u in a*ismbp-j+km g3v hg). living cell at 37 +h3*s j.v igpmkm)bg-$^{\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 pressureav r dxsck2t1t,,vtac 6pw6-y:kxcb: b m38e) 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 urani3i 4ci4rpn yh ;gsyk75um, $^{235}$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)0 3/d4lgifm ztv mi)u 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 h6fmhuad ,m jj 32;z 382ae hlfr3s0fg0.01 atm and the temperature is (a)z3fs3 jhrh0h6u3 a8 lfdej ;f,mm22ga 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximatwdysf- ;v q-wb/ql f.-ely) if the humidity is 50% on a day when the temperature is 25l s-d.w-wyffbq /;-vq $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place wherxl7s xfti92 gzz 76+gme water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at gwlft3 o tp)3 fm*y74aa particular place in the mountains is 0.72 atm, estimate the temperature at whi*3)4 a3 ypgtflwmf7to ch water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 53l-(pw(( jy m tbo-ujq;0 Pa and the relative hum( wtpq- l(-uobym(j j;idity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day whe/- dw(e 5tthun2q3h5-:u g6y xbv1gysi +pjqkn the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure insibxo**+ /nc ysp(w1pp:ysl : g/yu6qun nm8p(hde a pressure cooker if the water is boiling at a temperature pppy * hnn :/umbsw8(qs gc+oy6:n/1yxl u(*pof 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a roomqrq h-cqn (/o+ 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 poi*u w6jt:m3zli nt 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 96sgaydz+, sf:vim9 *h(s hotdiffuse a distance of 15d+igsso 9t*9s 6h mvfaz ,y:(h $\mu m$ 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 tij 0ifh*(d +hr 0(munmgny tubes called tracheae. An average trac*hih (0g(udmm jr+nf0hea is about 2 mm long and has cross-sectional area of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been calibrated u4c 1 3k8f0 5pjhu /gdwjvqmr n.i92npat 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 mygawuc)afps o14;j1t *v6 5ameasure 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 cup9ujq8oppq*gur2 (5s4lv6v+r dd psb) was calibrated at normal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the q +sgd5o )6ud 8rl9pqr 4j* vp2ps(vubwater 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 atmg,9pe1eqa5 0rgb ;lt2gtgj- i. After many balloons have been blown up, the gauj5 1a -02eq,g;ieb pgtlgtg9rge pressure has decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.1 m, swvnc,;4:;tf , 2m :rd *zvyrftuhuji6e7m/q and height 2.5 m. Assume the tem2qmet r6u;j4n;,:htv:7, duzws f/m icr *fyvperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is aboutapamhvd0n3d2: 20s mj4qk :jd 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 attainabl( r6n.d(k fjl5z1 xw s.tsyex1z :(urp)kc3ube using the best available vacuum techniques is abou tx.cj1(y u bp1wze56fk(d)s:3szrulx nkr. (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 ;rq dfe-z-8cfm below the surface, to what volume would his lungs expand if he8 rzq d;-ecff- quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a speed o+tdp,q xi ,sxs 6 kpfwu)0i+5uf about 40,000 km/h Molecules (assume nitrogen) sips5,s6d),uwfq +0ui p + ktxxtriking 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 injxs, omi/7mmy 1 d.qf)creased 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 of 77n /r/unx3 o(1xq02zizqk i)wjc v yf-+0m$^2$ (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 pres8m62t5npg usiy0 t,v7fy.yk7e s a*qmv qto54sure at the surface of the Earth, estimate the total number of air molecules in the Earth’s atmosphervyts0 sf2y7 5.mn t, qe4 g*7ykqtov5pmi86uae.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contaqm tv1 gu( /llf1qvzirmw jn5 (a8;65pined in a 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygen used in a hospital has gauge pre v vaqc)6fqck5i l 7 3w.h0ovadocj. by9;-;tfssure = 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 2.4 L/m; qco afol6bivv j.)q5a3kf-0tc7 9w ;vch.dyin. $\approx$    hour

  An iron cube floats in a bowl of liquid mercury kzg86ddna +* qi fl8uh0bu0;p 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 gasoline txn n;;ot0g*h 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 thjupir- 9ag ;x;e 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 tightly ontoq.n*8mpu-i 9nfz170krg k ohs 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 staojs*y8y;8 uio ndard, adopted 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, has aevm 9thj8 cd68 pressure of 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from the Earth ijp oz8zb/ltbv . 83y:ws $ 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 i3ha .1b5i(bf whw: izms suspended against gravity by tennis balls thrown vertically upward at1b:wh5w. 3mzhab i(if 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 3.00-cm-d2cbalx fzc,u.+2 nr-f iameter (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. 2 nufaf+-cc zx2b .,rlHow large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the c6de uos+tv.5c)kk: tair on the following two days: e:o kckt ud+6st).vc5
(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 1xuihna u9om amie f *-u3)3t,4r3ltlSTP, and when it is a solid deep in the Earth where the m ftuoe3u 3ml-h9u3 ai4x*trla) i,n1temperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, for an ideal gas at constant prwlvy(,x6s3 kn.k) yg pv1y* eiessure, the coefficient of volume expa e13y(xl.,npy kw6 s)*ivkg vynsion is equal to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.

  In humid climates, people constantly dehumidify their ce4khefaix b(d:dc7:796 vkkf dllars to prevent rot and mildew. If the cellar in a house (kept at 2h6k( bkxc ka 7:d e79f4fv:ddi0$^{\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