Which has more atoms: 1 kg of iron or 1d nfm3*csw+p y-a3 jld84bwt lg,a q35 kg of aluminum? See the periodic table or Append 3w fnpbl 3+ml5c*ajdw34tyq-g8 dsa, ix B.

Name several properties of materials that coudl+ s nagrsxumrh*- 3o 5dw-9+ld be exploited to make a thermometers *-d5ohg rr9s+- x+u3wnadml.

Which is larger, 1 C d*v,u1t:qk5 m(gw hcv hyl*6 y$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in theesmqvp +dq8;,rmal equilibrium with system C, what can you say about the temperatures of A, s;8 ,evmd+qqp B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. r t/(uwfxxav;6- 41 uzb-tdpdWhen heatxt v;dx b6r(-d1uwpft4-u za/ed, the strip will bend. Which metal will be on the outside of the curve? [Hint: See Table 13–1.] Why?

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

The units for the coefficient of linear expansio e1k, thas zt o7uoxe3h(*)k:on $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple thermostat used to control a f.4 -qkxon cls3urnace (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 thocsn- k3.xl4q e furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at the ends41gwl, xn 9ptd often have a section in the shape of41gnwt9xp ,ld a U. Why?

A flat, uniform cylinder of lead floats in mercury a7ij0lxth pyfj)3,+q at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass therma bo5gy ,+ec08pwon: tometer is first placed in a hot tub of water, the moy aeop8t:+b 0cgw,5nercury initially descends a bit and then rises. Explain.

A glass container may break if one part of it is heated or cooledsoy-rovff+i2 8 3gu 6t more rapidly than adjacent parts. Explain.rsof 23vyuot-+f8gi 6

The principal virtue of Pyrex glass is that its coefficient of02nc30kyl6ccdr me j2 linear expansion is much smaller than that fcce 202ym6c r0kd jln3or ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate at fok/e5 gd *pja-z:.o(s +znms20 $^{\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 sod 2 lfxq7i4x- v6aoedeky+:-qna will cause its bottom and top to bulge so badly the can willyxvf i4-d6ka2q e7e:xloq+n- not stand up. What has happened?

When a gas is rapidly compressed (say, b(vtb942k0qu zvpuvh 2 7 qbh5n2rwmz;m v3ti .y pushing down a piston), its temperature incre9vt5vwmnt7qrb2 u4.phk ;2 h u0 3bm(2zivq zvases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant forsqurvs 7dpjbsv47q.,8f3ci5 ce on an aluminum sphere submerged in water increase or decrease if the tempervj7c 8 .q 4vfqs 53i7sbdur,spature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law fo-f r3ou;,d vzyllows from kinetic theory and the relation between average ;3d-,zo frvuy kinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s o9v;3pmrqj v/law follows from kinetic theory.

As you go higher in the Earth’s atmosph v40tl4dyqvqhfxq7 , 8ere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an objec8p8;tl1fcnmm*7gcf d t must have to leave the Eap1ct;d8gn f l78cm *fmrth 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 practically no atmosphere.

Alcohol evaporates more quickly than watermy2 x+psh5gv9 at room temperature. What can you infer about the molecular propertip+9mhg5 v sx2yes of one relative to the other?

Explain why a hot humid day is far more uncomfortable than a hot dry day at9ou h ,gsdt:8o the same temperature.8soto: hgdu9,

Is it possible to boil water at r72kqwjbaq +p0oom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is t 8tqi tq+tj.ir;be4y0i qrf -0he same but the humidity is different. Which is more dense, the dry air or the humid air at t4ir0eqt -f.+0ti q8; itybjqrhe same T? Explain.

Explain why it is dangerous v,eplc 6bm 1+d.)y8qyzjrs *g to open the radiator cap of an overheated automobile ez +rqyv*pl81g bmcd6) es .jy,ngine.

Why does exhaled air appear as a little whc4hop sv lgy(n a *u/a.zg2q.u rj+32rite cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram copper penny?uruxigyu7 ,) b 967t t/rcr*lg   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the num.3p vn+ 2kdju/40s/l braevaxber in a silver ring of the nr/ adsa40 /bvpx jku.v32+elsame mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 6on l u:k.b,,u0nt en)y8°F. What is this on the Celsius scale?tuknnebyou,.,:l0 n )   $^{\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 tempeho7auy f:ie.5 ratures 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, thv wmjv(ng nf/wc 5y7wf 0r7+:qe alcohol column has length 11.82 cm at 0.0gnqwry7:/ w0mf(n +5j v7c wfv $^{\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 slqzc6x61gv8dsuf -d m 8abs 12 m long (20 $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

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

  The Eiffel Tower (Fig. 13–29) is builtp41t n+synlw u18* tal of wrought iron approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and January (average temperature of 2 1yp8 n swu+4 lantl*1t$^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, rivets ttkkm 6)qx8hp6 hat are 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 r6kkt)m xhp8 6qivet 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 ate5 hx+b wf0bxh-4i /(oy/*duo-wn vvq 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 hqmw j p+imy)( f7zmu+-d1c0l.75 cm in diameter. What will be its change in volume if it is heated from 3(+f)lu 1zd- c07mij+q ymw mhp0 $^{\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 1rsc-8/uxa3pm 6 xvy .f00.0$^{\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 water7vmfj) fu,.;;)d foetj1kvj j 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 e2 w7q)b+3o d a,igvgxmade 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, narrow3ge9q5eo6 9 yc 7 /pfnnqp4w b t;6meq5xm,eot vessel so it can expand in essentially one direction only, show that t / nb4yp6pw5ogneqqxc e965eetqf39; ,mmto7he effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the changwb9-olqnjgd5++ ed(f6gv/ua 9yg 9 uge 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 ycatjkzrl em/x;w;b0x8z-0) uq8+i g) a+zqoof linear expansi c;z)guz8 la)b+0q ema;+jr0iyzqtok/x w8-xon $\alpha$ 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 isotrop1-(lflk to;f aic 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 perfecm7*wzb .q 1n-i sy*apdt time at 17 ysm7dp q*b-naiw*.z 1 $^{\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 diameterias8jw9h 0.y e/2l7gz 6ha h:tva 4c 8srzq4dz of 0.140 mm. The bulb has a volume es904s62y 7hhlzvt : /dgh a wq884ajriazc.zof 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 c,q 9l5:pczg/ m)1rpvpsx- rxy ylindrical wheel of radius 0.41 m is rotating about its axle on qcv/ppx-,1mgprsy)zx5 l :r9 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 when at 15°C. Howytkf5q+vx -suo2l+pp)r++f4l0 phgb much stress is required to keep it at this l x2po k5+ ql+tbg+pp yl+s4fhf-0r)uvength if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steelc.4j )gl)vz/ :uy.kewmyxdm sa1b )mt52lf 0j I-beam of cross-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 20 kfdpq)rrz(2a1:y vs 7$^{\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 Kel5xxnktq* 8/ud k8em 3kvin 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 /jdqjb q3r)c. Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun ai2uf8o g.c 0je3 5ffrvre 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 atmosp+r5nce6mt(y m; , bhsi p1yeau+ id0y.heric pressure and a temperature o+ramhmyn ebu i5;y d,1.(s+eic6p0ty f about 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density ofawuo2. /l 6mez oxygen at STP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kgcfs/qq ;.x5 jz of nitrogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.5 kg of nitr3ejpj xo-: my.ogen ($N_2$)
(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 heliu/ czg g c*b5jniyn)()qm 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 conta 3ls;ezz+d*mu(pgwv * iner holding 105.0 kg of argon gas at 38vpzdwm*;+*u(g s 3e lz5 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kgc hw.z0 2r*uud 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 inst6x-6i rqjk+ fxs9iijt:ke sh v0k2)6ide the balloon, which makes it less dense than the air outside. Supp0q6t:6j sf)kx ii 6-xtkkjv2e9h sr +iose 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 15c vlprb8e:,y.y n7x.denz -d: $^{\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. 9xuzumnsulxb 0o108h-8op* n0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand at sea level andn945e+lq ieka 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 molej+spej*dqek4 8 cj 4p1upmb 9*cules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many molecu.+su 0t q ;ol+mmgpx;oq3 adw*tbq r),les?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) moles, c;3k3uj2 p6npbftdn5    $ \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 5nywkw*ikph/e536ld* elj ;b*5v /v zf6in- na.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 werep8g: g-(lv+r mz o 7i :am.hjrzc k2ao;xzl4n: also in the last breath Galileo took. [Hint: Ass(m4 8ag+z .lg2 ;romcrx7 :iozpa v-lk hnz::jume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kin1cj 4lg gl z40bwfet88etic energy of an oxygen molecule at STP?j8b4tzclewg4lf 1g 80    $ \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 nea2peif6 -y2 w2g3cbsc zr the surface of the Sun at a temperature ob cicysgz 2622pe 3-wff about 6000 K.    m/s

  By what factor will the rms speed of gas molecules inch c5(;anqozu5xs z9/xrease if the temperature is increased from 0n;9c o(uxsqz z/h 5xa5 $^{\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:)*e3)qtsf fk n4lgqq5 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calcula*e) lgqtq n3)fk qf54ste the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a mzy-q2d2,cb1qig bw*/ j m ,oogas 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 con;vsdpa: a0 bw(:hm, xnstant, by what fa pba:hw0 xvmns (a:d;,ctor does $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is gidqt l6 o)iau-2ven 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 temperatr sunvmeqa :ix7eg9 78b/9ne,ure, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their mole mqexvne a7 8/:s9n ,7ebui9grcular masses.

  What is the rms speed of nitrogen molecui 7w;8all0cwl les 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 molecule at 0 s tnew5 j9lqk9f5w 6gl)4x*gi$^{\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 ni5l, 11sa brzidlqb9 x:trogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u in v; c7 i8czew xcxni/+3a livin; nv7 c+cze/8c iixxw3g cell at 37 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a gas can be writtenqrx h 4*dgys,lbvd1 . 88u4wwt 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 urs yigq;xd+ 1-hanium, $^{235}$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 pres x8x.pb:i)dw nsure, in 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 0.01 atm and the tempevdr:;umahgy ey xp6x..f9. u*rature is (a)xe ;.v p9.:.yxyh u dgf6ruma* 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the h tk,/-jsu)pbtumidity is 50% on a day when the tempera u)/tsjkt,-b pture is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place whe7cbiyii uc v)w+ :zfm7xkq2*, re water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at qkoc+;*j v -yfgjuyx ,ol14n 8a particular place in the mountains is 0.72 atm, estimate the temperatjk+u; ,*gqy1 8cx flvjyoo4n-ure at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of waterh71om2 fl6i yi2(vnw i is 530 Pa and the rmo26 h2i1liynw( 7fvi elative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day whe( *1npaore; hqzwki,- n the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the wateh;0:nz-l pnmkr is boiling at a temperature of 120n l;0n:p- kzmh $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of volume u0ul.b82wi+ w ikx-ks680$m^3$ 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 d /4ocw8f2gko yoqf 8+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 gl -hnsi.y*,i. jet8ugtf8z 2v raoz4s9 ycine molecule (see Table 13–4) to diffuse a distancygj e,.t9fzo.z-ti8u8 sv2n*is 4a hr e of 15 $\mu m$ in water at 20$^{\circ} $ C if its concentration varies over that distance from 1 mol/$m^3$ to 0.4 mol/$m^3$ Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u. t $\approx$    s ([color=rgba(0, 0, 0, 0.85)]Round to one decimal places) $v_{diffuse}$    $ \times10^{ -5}$ m/s
$v_{rms}$    m/s

  Oxygen diffuses from the surface of insects to the interior through tinahe s9v70idq9gcy4tz w*8d a+y tubes called tracheae. An average trachea is aboaw7 dscdi y9 0gze*t8+9v h4qaut 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 at srj44un) d1 ntxoz.75uzj 8 pnwf1ec220$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape measure has been calibrated at 88-m-djio*r4fb ixuut2rp7 i 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room temperature. How much error :dx.4sypx4w7okqw h tx0lx;,will be made in a recipe calling for 30k,xtp;dxq4w0: .l yxso w h7x40 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 helhw8o/5o g0oa)xryx p;y au- d-ium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original ;d) 50oyu8 -hprga-xwy/ aoxo gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.x m0 . 17kqfprtso4:j,b5wxj r1 m, and height 2.5qx1 o x7t0mjk:s fbw5rj,r.4p m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about16xr-fxzbq3 p 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 us z ,e/in9 bl8bw4i i79tns(dpqing the best available vacuum techniques is about n 9q bi(9z ,ep/widl7bti8ns4$10^{-12} N/m^2$ 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 wh80wyd+zahl5zk w e;i6k ,ca, 7tiqj*hen 10 m below the surface, to what volume would his lungs expand if hzh+k6yea*ihlw qk ;da0i85zw7t ,,jce quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosph8fy-3.x7px:oyvexif */ycfr *ozulg(5 p j .mere at a speed of about 40,000 km/h Moleculep:- pcyey*i rvj l.*7x fuyx.x(ofo385 gfz m/s (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increa ;li2l ri0,zucsed 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 ois+4) nwyc6*ws ezp(b*i e la,f 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 p wuk.o7xqn /4eo+ ;i 1dmh-nxtressure at the surface of the Earth, estimaxi 7ht. oekmxn/wq 4o1-nd ;+ute the total number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contahzpk9695g*e gb*kovjined 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 pressure = e 0fh7 as5vp8r,q vjb.2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last i0 a8br jpf5v7hevs,. qf the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of lmgatvwr0rg( 2a 2r u2+iquid 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 gasoline at 06,uz9p wt: foffbek.k 9r( u2b$^{\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 equato kz, ffq48 epswdt-no;n54ak f 7u.tt*r at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto a glass jar at nabhv h)32ugya4c941wuo* p u20$^{\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 standasviunn p w mw.59ro43n68ca:ard, 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, h*na90qnl 3fb vd*pu:kk9 sp y,as 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 Earth is -0q2 c/tnq kh yr3ms0ch9cme7 $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennis balls thrown vertszcl +b-bq0 m:542rkfy fuz8pically upward at it. How many tennis balls per second must k+bzf0 5pu8-2 lr fbqc4syzm: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 (sphericig8lcjb (*nt 1;;pcydal) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large 8*c1p biycn;j dtlg;(is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the following two days: ksu49)n w ,zyf 23e kf:pc;bwkk p29e3)f;:bf4ck,uw nkyw zs
(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 STP, and when it is a-f xn(xsd gl58l,yeglh: ooa 6tc.),m solid deep in the Eaocy(,f-)x6ngg: s o5,a. xmlltlhde8 rth 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, for o g ..nkwmt.rt9ae:j-an ideal gas at constant pressure, the coefficientam..o -j r: g9et.wntk of volume expansion 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.