Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the p+gk0cf5 j (egperiodic table or Appendix B.g jeg0(cp+5 kf

Name several properties of materials that could be exploited to make a thermomemx 71yckj7)yjh5 6oyctykh76m) cj 17y ocyjx5er.

Which is larger, 1 C0/mi .m0:qk tbto fr2l $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermh;;kbfuk.:k5 h/viko7nqhk : al equilibrium with system B, but B is not in thermal equilibrium with system C, what can you say about thk/:k ;; nkbq 7.vhfuih:o5kk he temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. )zul) tii5n 8l:yu)d- y jy-bzWhen heated, the strip will bend. Which metal will be on the outside of the cily) z8-- j ytz))i5dlu :nybuurve? [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 expaxfaowukh7:j0je1c)5e* yj9 . r 0hod unsion $\alpha$ 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 contrhmcr .ga,- *rbol a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together.mbra,h-r. * cg 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 ofte t huj5b(wn4m+n have a section in the shape of a U. Wun4(jh tm+5wb hy?

A flat, uniform cylinder of lead wo;+(ud na;2 e gbpsv7floats in mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is first placed in a hotbcp5 g7ku7 d vuuwnd+-a7fd1 8 tub of water, the mercury initially descends a bit and then rises. Explain. fg-c87u7u+dp1a b57wu k vdnd

A glass container may break if one part of it is heated or cooled m3 mx2-tl,-sm +nrq/karkiol:ore rapidly than adjacent parto-,/rl 3m tl m k:2xi+nskqa-rs. Explain.

The principal virtue of Pyrex glass is that its dwv)k 3)bycu g7:dvd8;fgyz m-,ch ;ecoefficient of linear expansion is much smaller than that f)w z y vgvh3 8ymgef;c);c, -kd:7ubddor ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clo5.ywpci2yf3b8m 41coz;d)p kskof e* ck, 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 9a x9 2;mespl oa+-fob:n6dq qits bottom and top to bulge so badly the can will not stand up. Whax9o mnbes9q:6+qd-aof ;2p lat has happened?

When a gas is rapidly com(;-1mjxq 554dbr vo: vtbhfcgpressed (say, by pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic qrbv vg-14;cdxh5(bo mf: t5jtheory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged in wateufswwtrdi l 5(+/p fzeu/*z 2(r increase or decrease if the temperature is increa /l ipu 5zuws dr*zfw/t2(fe(+sed from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Cha* m0 csq( gy*tb im2hx(hu1s7xrles’s law follows from kinetic theory and the relation between average kinetic energy and the absolute tempmxu* cs7 is*ht gh((qb12 0ymxerature.

Explain in words how Gay-Lussac’s law follows from kinetii:0c4s7c e/-kzu umy lc theory.

As you go higher in the Earth’s atmosphere, the ratio of 3vyb+a- 3 tssbot myu30j2z;n $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object must have k3 h: zo d:8axk- 74qb3y(ow zeeihsl4to 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 whbqo8:aw4z :ky7- eho 3e(i3 sd4xkzhly the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What can you 3 .:benps2q16 pu1q:sacuhbi inferb.hpqnsa uq:1 21 piebu3cs:6 about the molecular properties of one relative to the other?

Explain why a hot humid day is far more uncomfortable than ahr-a /a7hq; jc*.ep sa hot dry day at the same tempere7s/rpchj;q-. a ha*a ature.

Is it possible to boil water at room temperajx52ew*txs:1*aq i2) alzaxature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperat0;tzfq r-3p 0,y. d hv33lh4goimup hwure is the same but the humidity is different. Which is more dense, the dry air or the zo,v0h tfhrqw.l4 h3-um33d;py g0iphumid air at the same T? Explain.

Explain why it is dangerous tosuz sj1oev 5-+cq-t;r open the radiator cap of an overheated automobile engisu-ve5z rqc+o j1;-tsne.

Why does exhaled air app 7l*rie1 )n0ixvz-odn ear as a little white cloud in the winter (Fig. 13–28)?

  How many atoms are the5e+am v q; zwss4;h*wrre in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare:)+7 m2wjqxoa4 *g4gtzc9 o5g cxvn jp to the number in a gcxnoq gx52)*w7za +cvo4p tjmj4g9 :silver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is otc6p3lwhz)c/ :ey whid /8m7uo7k nj,ften taken to be 68°F. What is this on the Celsius scale?l6pjd w7)hiy8h,o e7/ct kwczm:n 3u/   $^{\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 temperatureshv mrcbw ;y1:yd)k zk kq:8jbyr8*u23 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 thermometer, the alcohol columdn/egg7l z( a-4qgnn8n has length 11.82 cm at 0.n ge zd4ln-aqg(8n7g/ 0 $^{\circ} $ C and length 22.85 cm at 100.0 $^{\circ} $ C. What is the temperature if the column has length
(a) 16.70 cm,    $^{\circ} $ C
(b) 20.50 cm?    $^{\circ} $ C

  A concrete highway is built w z wbtz9wg/ vc5/86pgof slabs 12 m long (20 $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

  Super Inva$^{TM}$, an alloy of iron and nickel, is a strong material with a very low coefficient of linear expansion [0.2$ \times10^{ -6}$(C?)$^{-1}$]
A 2.0-m-long tabletop made of this alloy is used for sensitive laser measurements where extremely high tolerances are required. How much will this table expand along its length if the temperature increases 5.0 $^{\circ} $ C? Compare to tabletops made of steel.   $ \times10^{-6 }$ m    $ \times10^{-4 }$ m

  The Eiffel Tower (Fig.u- :j9n)itd r(ikx-kdq7 ycc/ 13–29) is built of wrought iron approximately 300 m tall. Ey n u7)j-idci dt kqc(r/k:x9-stimate how much its height changes between July (average temperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, rivets that are larger than the rivet hole are oumiardy7at s)c:9v w 54iue+ta6 a*3dften used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A staiei7 ryvc m: u+d)*dsa4tu63a 95wat eel 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 aty-0) wc xq9twvwnz35 vfe,d,z 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 i b e,pfdgu.tvb*-s ,tx.6crz1 k5 po.on diameter. What will be its change in volume if it is heated from 30 f.p5-6xr*kc.bde to ,go z tp 1bs.v,u$^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL of water at 100wy9t;qen6)w 3vl6f e u.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 vvh 8r/zp/,cxat 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 place 2a/ddbu )p(zgd 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, narr33ja ppny*zyv)d) ri:w) kmg) ow vessel so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximately equal ):)ky zrp3)d*a mjiy3pg)wnv to the coefficient of volume expansion $\beta$.

(a) Show that the change 6zrm f2os*,pv3 ock1a in 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 width w has coefficient of linear exz6, zz: i)e)z ybe+qx:dah9zkpanxbq,za):edz)+yh9zz6ki z e:sion $\alpha$ 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 )dl- e+ozn9sl6xruqbu)8w + anu* ej: 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 and keeps perfect tbof/i 1bo*d.y drx+p4ime at 17x*bo obiyd./ p41+rd f $^{\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 diametesr zc:ppk44-),n6u7 xallr4 nf ;flvwr of 0.140 mm. The bulb has a volume of 0.26lk4n: 7pfpzu 4lxn-4l r ),;afcvwsr55 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylindrical wheel of radius 0.41 m is rotatig*p ,; dqi bgzdb1/4jv1e+w aung about its axle on frictionless bearings with angulj d b;*ge/pz1 qia4v+,u1 gbwdar 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 .xqdy /rw1u, ethe desired length when at 15°C. How much stress is required to keep it at texu.w,rdqy 1 /his length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-qaif/lo8 0hw: 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 134.122 cm at 20f/7v/ 1* v0soeob 8y9ana qnck$^{\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 Kel:-mwh heiot(m oh-p(6f 3 no4cvin 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 Fvv6g mxay0 rrgwkle ;92 (pj17ahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are abou5iz6zx5/kcgy( e) bcut 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 atmospy oescd2jor67*g 9epm2fw/a/heric pressure and a temperature of aboy /c/2f ora7 6w9 *pe2sgdomejut 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 o6m7qw - ha/ t8k 13gzluyreu+pxygen at STP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitrogen (m+lgqz,euxy++c/e/ l $N_2$) 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 nitrogen (3: yei 0py0ov (reweyy,pznk ::7mf)zj)es6 n$N_2$)
(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 atbslj/q d/n1mtn,u d. / 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 aq,ulr t:vb1.d 35.0-L container holding 105.0 kg of argon gas at 385 K,.t:qvdb1r lu?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg mm38o-(hd fj0mu e vw8of $O_2$ 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 achieves5 r- ptlykqqit8oytz7+ engwvxx a0t3y: -1.* its buoyant lift by heating the air inside the balloon, which makes it less dense than the air outside. Suppvey.7g3ttp y lwyz1-r-it: k0*o a qq5+x8tn xose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air at 153zxn f4a/wbu, $^{\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.p. o/re9 1e8(x wjtijo0 $^{\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 has z:f *upl:t.5 fh/s 9uniqq7le/ jp od5s(-vund 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 mol/d al ki.r:1xsecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many molq3 c qlwa-1,u .)a61qaiiqbda ecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) moles zj3 t/ o,/fyazwqw3,f,    $ \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, j76/xv(h 7zhi3u buu+ twgcge 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*ibjk r:y0 3*hvu.kd wv.lk;m in each 2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of c v;bl .ky*vhkk rwui3m*:.dj0onstant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen moleyn6qp9yd2jw(ir1 qbv (:v oe7 cule at STP?9den(6 wqj72brpo:( 1vv yqiy    $ \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 t j/aehch :bz8d; c::u)jo* pbshe Sun at a temperature of about h;cpjejbosz:/bhu a*d :)8 c:6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if the te) y5:v4hs+mrlye b xo1mperature is increase:yblymx4v +5o1 r)eshd 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 units of km/s: 6, o *hrppo5(/y0eqb w1 u+s9aoo 2, 4, 6, 0, 4, 1, pr0 +5pe9 y( hoob woqusa/o*18, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of mol2w8vlrlfj s b/ 9yr-(necules 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 volume is held constaip8km2dr -om./j sf( fnt, by what fac-/.8oksjm fmfi p(r2 dtor does $v_{rms}$ change?   

Show that the rms speed o.9 ekj2 cylaw bj*/8zvf molecules in a gas is given by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two gases at the same temperaturb j2-f:yr9qpzpq eea. x8:xd;e, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecular masb:pyx2. a reeqx9:j8d-f;pzq ses.

  What is the rms speed of nitrogen mo85p,;rq8o:wu6n lt dxt nyq3jlecules contained in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygen mc 9uk 7l7u g0yxi)le;iolecule 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 dqk(( bk. nwb-jistance between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino,df g5ll 9u.jd* )jwwo acid whose molecular mass is 89 u in a living do5,l)f 9udw jwgj*.l cell at 37 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a gaftn,sp/g c ict3(ph8jyxlz +mw+*q ))s can be written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uranium,gkfmc,n .kd te)fdy + *).ihm4 $^{235}$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) 0h)(bwwbg2ii *f2rg c m1zqletgc;1 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 bsd/j y+2)ffknvhn +n7b.f 8k when the pressure is 0.01 atm and the temperature is (a) 90 vfhf dbf.k+nk b/nj87+)n2sy $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity i7sr/yqy ecw-*s 50% on a day when the temperature iy /yqw c-s7*ers 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water bomwlb ;- 20sbbx2qqsn: ils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72 atm, estimate2 rn3es)u9 skq5)atbz the temperature at which watna b3uke 9)) q5s2rtszer boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the n;k m0a4 5t2;cwhy)iqu/ zwszpartial pressure of water is 530 Pa and the relative humidity is 40%? 0ntzc/4h)sk;qw im 25awuy ;z$\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the tok0 ):j.yah viemperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure9nae8 *myon i5 cooker if the water is boiling at a temperature 9*m ony 5aeni8of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a yl ozs,cv*5 l8room 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 odz1njq9c4(rfk *jxix;o, naj+p e+ d, f 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 mox-in fevj4i;*lecule (see Table 13–4) to diffuse a distance of 15 -f x*i;j vi4en$\mu m$ 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 suzbev ,zx8dm*kbxpxl m)m4og p 7)8d2/rface of insects to the interior through tiny tubes called tracheae. An average trachea islo )z8bmd78xm *v2ebg/x kxdp4p )zm , 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 32vfwb:btzw 9v 5nir/ n7p10)z34kx rdo rjxihas 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 precise steel tape measure has bc:3* ug4bhkv10mp ukheen 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 n(k8fr p xn*4ddormal room temperature. How much error will be made in a rkfpr n(*48dd xecipe calling for 300 mL of cool water, if the water and the cup are hot, at 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a helium gas cy-u p l8b;*o3qyv ja;jblinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What vb3j8;ljy ;apqou -b *fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of leo qf3) :xbub2hdul7g:v fql1. ngth 6.5 m, width 3.1 m, and hf:xolqlvb1) q2.bd: 7hg fuu 3eight 2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matt*bun8v ; )pcgqnv t;h/er 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 b*nxt;d-;g /.v+gazo bzige6h )y ,uk techniques is about -z6ga .,g/)nx*+bkz ivg;etdy;o hbu $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fillsmp17j-c:in20 mp +5snbpvx gv his lungs to full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he quickly rose to th7g0 v2xpm1 nj+:isp5pcnbv- me surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a spee75nl 5wr1z ba pyyaw5 ,mc36imd 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 szl1am b w3ya5, cniwy 67mp55rpecial materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of a (zqra, avr71fn mu*q0n ideal 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 volumeobu57tg .hdk/+4w,0o l qyyxr of 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 30/ecg2 u1jvbwi3qv rpressure at the surface of the Earth, estimate the total number of air mov3bic03rew2 q / uj1vglecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules i kbonbsslw9rhj- *2 k- 921cjcontained 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 gaugpl:od*tna7thbv ; e-.e pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric presa-ehtd*;ton 7.p :lbv sure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid mercury at 04zzb khq9rd02 ( b,ve:*k ecl/zwwdu0$^{\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 aa.kgmpd 8. ef7,u+ viqt 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 equatorej/e2 zwl:;;uyw od 2-gop5ri 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 t8 j5 1tysruia6ightly 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, a0 fhu roau4-st5h --ludopted 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 c +r6b2a mlu6pnharged, 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 fromi5 dsndcmzss).g8 p,- 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 againsttoq2rjx sw ei9s82/e(q*m*of gravity by tennis balls thrown vertically upward at it. How many tennis balls per second mu*w9 (so/2qresmqio j f8xt2*est 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-diameter (spherical) bubbl.4v/(9x. 6p wptzxjylm oi/tqe of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air blpztiqvmw64yj( .p.x 9/t/x o ehaves 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 days:3u77kq ow;+gie 4vs w9hjbggp( 0n4za g s 74i;+a4 g7wqpj eok0vwn39gu( bhz
(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 hfil u u9ve-tv.*olx*i .t( 1hin the density of iron at STP, and when it is a solid deep i*.u o eu-v9* ix.1ht(lfhlvitn 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 show that,00 3c. cwbq bk+c8pxzo for an ideal gas at constant pressure, the coefficient of volume ec .wx30qcb+ 8c bopzk0xpansion 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 const 9iwcdme a4e:qo*3yya6 ke.mxf;z ql-i+2) tp antly dehumidify their cellars to prevent rot and mildew. If the e:-.)iq9k+ wl yxpoemc2m3atd; f6ze *a 4yqicellar 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