Which has more atoms: 1 kg of iron or 1 kg of aluminum? See t n4roowsvce)5qd6k z 7 bqy)08yq68xt he periodic table or Appendix ysv8xt 046r k 6z)oqc eb)5od ny8qw7qB.

Name several properties of materials that could be exploited to m0 u9u)k5f 13vee yniapa7vlz,ake a thermometer9p57eike z,l0vy )ua vau f1n3.

Which is larger, 1 Cyg e:fz-erd;qxz 60rin lpd q(1-;gy2 $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibri j5;ybk3ly 3rlum with system B, but B is not in thermal equilibrium with system C, what can rk; l3l yjy35byou say about the temperatures of A, B, and C?

A flat bimetallic strip r 5)d4nsartb*iv z/kw*whm:e 5 ft33 bconsists of aluminum riveted to a strip of iron. When heated, the strip will bend. Which meta nsz* 3i eb/f* :bd3wh5wktvram54)r tl 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 linears wt ) om :mb t84daw,/xpmpsps3750uq expansion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simple ggwgs 4xz;f3dktg, 4 jin/dlx6uzz7k:,e5 5x 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 it can be set at differelid k4gkx73ntg ,s/e4fd,gz:xu5g5w zjx;6znt temperatures.

Long steam pipes that are fixed at the ends often have a section in the shape ofnogm4gg 7:: lygi z+m8 a U. Wh78m:gzg :nglym+g i 4oy?

A flat, uniform cylinder of lead floats in lkdf67evb 4fc 2qeq4 9mercury 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 hot tub oe/t5rtd ) neq0 rjo):cf water, the merrj5dtno0 t /:ceqer)) cury initially descends a bit and then rises. Explain.

A glass container may break if one part of it is u*pep o s;l0(qw. vpn)heated or cooled more rapidly than a. p(nlue;q* o vpw)s0pdjacent parts. Explain.

The principal virtue of Pyrex glass is t al,bn6m n/x,c(7se euhat its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance,/nb s6 ,7 emnxau(lce of Pyrex.

Will a grandfather clock, g .os+s fsen:q4*n.gs pf 4t1naccurate at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and top to bulge so bcvsh9 qt ;o:pt9 ;0;z4spyqztadly the can will not stand up.pz;:q pytq ;ssv9;0 htt4 9czo What has happened?

When a gas is rapidly comprq j2eo6b rpnnw-u3-t()bde * fessed (say, by pushing down a piston), its temperature increasn d(f-t 6*- rnee)2b3jpwuqboes. 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 force on an aluminum sphere submerged in water increase ,s w/3 fu5mw-r7pyffbor decrease if the temperature is increasedr,-f7 wfm3fswpuy 5b / from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kin 0tcmrfm 7.*l. dg-owfetic theory and the relation between averag o.c7mr.w*lgtfd0-fm e kinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows fromuv++i pd2z mz6eek+o ; kinetic theory.

As you go higher in the Earth’s atmosphere, the ratio ,ppik. p zhe (5ou1u*vof $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimu;h2 m+,mumnelvep-+,:nzn 1 dvqb em0m speed an object must 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 theud+mze v2nq+: m0 vpmnbne,;leh- 1m, Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room lra i*o- p9 h3/t3tfuh 1qsal1temperature. What can you infer about the molecular properties of one relative to the otita39qslh u/ 1a13l* pofh -trher?

Explain why a hot humid day is far more uncomfortable tha 0aj, dz6ijav i9t-/+v edb,otsl k)yq6+5qkn n a hot dry day at the same tem,ia9/+0kd5 sto+q -etn qkib yjvad 6),v6j zlperature.

Is it possible to boil water at room tdgkmn ;ncnu51x,. zz 8emperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air tempery+;co ux g djmvx5)9, toqak+-ature is the same but the humidity is different. Which is more dense, the dry air or the humid air at the same T? E xk5),+uc-agv;q9 x oty+dmoj xplain.

Explain why it is dangerous to open the radiat zc0qcz9 j3i-xuj62 jgvena8 h7z5q,lor cap of an overheated automobile engin qav x8e79gciuj-l2zqh, czz5jj0n63 e.

Why does exhaled air appear as a little w*5 j2.p sti qnyf+yw4ohite cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram copper penny4mavq5 m (v1g) u d-rjpyot*.r?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the number ina hzjaz y0 3z852*wogf a silver rz82zy w3gf0a 5zaj* ohing of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsius scale?v qxy2eptri)8 1nx5:hx)yt1 :258xreniv hqp   $^{\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 temy57h st45wtbdg 7 jhp96ab4 mbperatures 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 column has le0ke7r70tsm s)vqmqa,hi9 n(ength 11.82 cm at 0.mkq e,r q( 0a709hmn7sevsi)t0 $^{\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 o dgqo8+ve cn.(5g /horf 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. 13–29) is built of wrought iron approximwvb 0 7;fz*ugfately 300 m tall. Estimate hfw v7zbgf*0;uow 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 hpl7ubr5-f0 rare often used and the rivet ilr p7 r0bu-hf5s cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter at 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water g ;zgx7,nerdr:t 94oe at 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 dia( s ha3tm5cu kz0i,ot6meter. What will be its change in volume if it is heated fr5kthtiz cs3 a6m0(uo,om 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to th 9*qz h6pz pw:oncr vey9q,6l.e brim with 350.0 mL of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 ae-*gp epn ;- * 9iltmbkkn06smL of water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to be place6+sp:. dfw.cfnkm2/-vnu .y w6stygq d in a ring made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, narrow vessel so it can expand ih69hvia(3ed fgz b -;py u.hoy48 ltv3n essentially one direction only, show that the effective coefficient of linear expansion is approximate9b d8py3fo3ghh4 ; -lvt he6zy.auv(ily equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in 8*m cm4l5w9uk 3wunhm 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 plp 8/op uq*3qf :3yzfrs:rk0biate of length l and width w has coefficient of linear expansion iy 03 :*r zr:/fps 3q8pkbfquo$\alpha$ 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 soqspon1bok(-* . fdl4w 5y zvj (te6r/elid, $\beta$ = 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 cloc7fcho 5k w*g8,qnh5pn k is made of brass and keeps perfect time at 1hwognh8 ,5p k 57c*nqf7 $^{\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 diameter(c3 j (q-2vpuplwhfl ud17i7 z of 0.140 mm. The bulb has a volume of 0.255 i p(lh (vzl7pj-fqdu3 c1 w72u$cm^3$ 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 ofqciae ns 1;uv aoh8b)1b v(6k; radius 0.41 m is rotating about its axle on frictionless bearings with angular k ci8u)hb ov; ;vebn11(qaas6 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 w7xacle9a.j5 c hen at 15°C. How much stress is required to keep it at th 9ae.l7 jxc5cais length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-be cv:omlw8b8pppr25l : am 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 diameterbdxgf7t c(, le6d;u4f 134.122 cm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on the511 :l jg 4wswhj2 27o+usakpuv2yrye 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 temperature on the Fag5fn i us/l6by5zb iu:d24hr ,hrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interio 4 ksy,jfpp,1 7oa2tvejrz8:mr of the Earth and Sun are about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

  If 3 $m^2$ of a gas initially at STP is placed under a pressure of 3.20 atm, the temperature of the gas rises to 38.0$^{\circ} $ C. What is the volume?    $m^3$

  In an internal combustion engine, air at atmospherid 3jblu+sgvg29e9 8 i70agmfoc pressure and a temperature of abouggda28i7bfus9 9g+0e ml3vj o t 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at STP using the ideal gas law. *gi c, rtcs(gmvf74lf t:+sy/   kg/$m^3$

  A storage tank containgj j( 0g +bz/kvsgvok8he1f*+s 21.6 kg of nitrogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP contains 18.c vp-0 gviwfi hz r)9e-q+06ct6o8htn 5 kg of nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gas is at 10.0 /p 9kmk::cdxdt bsxkofo+ 84 7(keaw2$^{\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 w4c)gzg,b e5 ,lf3god-L container holding 105.0 kg of argon gas at 385 wg b),gcd53og f,ez4 lK?   $ \times10^{ 8}$Pa

  A tank contains 26.0 dz5(3xq;uv ew 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 c 5e;o1a +hyd+ebe t: yht mqs2m6ze3:buoyant lift by heating the air inside the balloon, which makes it less dense than the air outside. Suppose the volu1 2do m3:++te y:hbc;5eszqeamht e6y me 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 airnw-lg . dz)dpsfxsi- xs+x5k3s2) a a1 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 18.0nv95*5 q.dwc; /wdfmg,yfsvz $^{\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 sd57zqgt.7s9 d x odv(dxz7 oj+ea 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 m5u.*7l8z) nozrhlor+z4h vn golecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 pwj utm5; )5suL? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) tb9m cr9m-5he;wwzqo, 4 :yjpnpbp:5 moles,    $ \times10^{22 }$ moles and (b) molecules of water in all the Earth’s oceans. Assume water covers 75% of the Earth to an average depth of 3 km. $\approx$    $ \times10^{46 }$ molecules

  A cubic box of volume 5.1f:0j r sw46bs6 3dnnpl$ \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 moleculq8jl;kie, 2 q7xub tu e,--gdges of air are in each 2.0-L breath you inhale that were also in the last q -u -dlg,;g2tx8,eekjb i7uqbreath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average qhkpxyn r.u*1 (g+rf8btrhr-8* v/ed translational kinetic energy of an oxygen molecule at STP8frpr r8 n1g(-+x/ be.**qku hvyhdrt?    $ \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 atomb( v: 3vtk. g/ptmrf.ps near the surface of the Sun at a temperab: rt3 ../vtvmp(kgfp ture of about 6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if thdq-nlu -l;qli6 n,0a je temperature is i6;, i-unljnd0 qa-ql lncreased 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.whcj+a h kud t75vdjzqi: xv;u;t 881: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate the rm :8.5d8 7 jx;uuvqhj;vttdw+ c1zhiaks speed. $v_{rms}$ =    km/s

  The rms speed of molecyey5)wrbv2 ,vk s *j3cules 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 czq3,soox t/4bonstant, by what factor does btzs,o3q4/ xo $v_{rms}$ change?   

Show that the rms speed okm-, 0c(d bvbrf 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 temperature, the ratio of 71svkg,a:2n zjipkq(cr ;9cy their rms speeds is equal to the inverse ratiok 1(cjq k7c; vrzy: p29,gisna of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules contai4/4 h+u kaxx ij a5nklcwed+-0ned 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 fs0)bq/c sr4s ;z9 5ohjilpn*of 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 mf.rvr; rt+yrjf / x1:pcmy13iolecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms sl sq(kww2puhmk4v h xc:+/feq*f ;+ t1peed of an amino acid whose molecular mass is 89 u in a living cell aqf/qmh 4e uf:hvpwk ++(c tlkw2x;1 s*t 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 gasjl)u6hri qd 6*yvc, d2 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 ur2a 6t)b zgjcv hkvipv 1o8z:79anium, $^{235}$U and $^{238}$U (the superscripts refer to their atomic mass), can be separated by a gas-diffusion process by combining them with fluorine to make the gaseous compound UF$_6$ Calculate the ratio of the rms speeds of these molecules for the two isotopes, at constant T.   

(a) At atmospheric pressure, in what p,qbq3 d8m*j ynnsl h;.i9b;qx hases 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 clo5vn3f s0ny 7h5x t:pressure is 0.01 atm and the temperature is (a) 9 yt7:lx5vn03o hf5c sn0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on wui.v( i31)2ltyw7 :s dwxfvw se lr::a day when the temperature is lvs :w.wwy)7i1uxs r: flitdv23ew(: 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where wnmy;tak vr( ./ vjn-bt: a;j9+aqzo5tater boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mous go+01pi:t75 thoof e j 1db:pb:7pkpntains is 0.72 atm, estimate the temperature at whicpdj :okfoepp+gbt50s t1771b hp :io:h water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a drby4j0rs n pa 3;tf6ip ,g)v,:i s2qneay when the partial pressure of water is 530 Pa and the relative humidity is;p s fj30,n4 vp6rry)q: s,eibagtn i2 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial prespwar u1vp0zvaf6- +7x sure of water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate presim-7khf7zk 8k sure inside a pressure cooker if the water is boilinghmk8k-if z 77k at a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in ayf *i svcs/ tx*d:lpslhft3we( *(;b7yg ( ls8 room 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 ocqx4x4g9 5sk gf 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 glycixws0( qze-ip71 f+)vyyqoii0ne molecule (see Table 13–4) to diffuse a distance of 15 qxy7 0(zpqv+-iyi) 1io0efws$\mu m$ 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 through8qiw a wj(7 4 sd*v,mwybmls8l.4cs6p tiny tubes called tracheae. An average trachea is about8 c y,ll.4d(wsb* siws6 m4wqpmj7a8v 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 measur m* 1yh0j2jyrze 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 precise steel tape measure has been mt r:hqzih4ze4w bdm1 qq7v 12xka .20calibrated 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 calibratey v dt4k j mi321x7+5rp45znwsf(x lrad at normal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water( x5 34xp km r7i2wnazy jl+f5s14trdv 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 atm. After many b)c*nx2b b pqn0alloons have been blown up, the gauge pressurebn)*2pnx q0bc has decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number ofka5qxh p r*43 l-jlcp3tycgs2+)ax ) alfrz:: air molecules in a room of length 6.5 m, width 3.1 m, and height 2.5k la)pc25zaf: -q4 +t3h rjx*rpc 3a:xs yg)ll 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 ma, -8tlgca n2vktter is about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best available vacuum techniques ir c,a;m h:y7vzu2,col s aboutvha 7z2 l;cocr :uy,,m $10^{-12} N/m^2$ 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 luozym 9a*x 4mu5ngs to full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he quickly rose z5ay 94* xoummto the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmo;2 .sf jq r b0p;(gns:rgetjn(nbw0w0sphere at a speed of about 40,000 km/h Molecules (assume nitrogen) :rge2sr.b g;qj(s( ;n tpnnj w0b0f0wstriking 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 increased g gk9nv;-rw80hj rn)v 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 n4(d*qexjsz0 2 ia) e)p+cvhw 770m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at the surface of the Earth,fz 4r6csu48b g estimate the tota gr8b4u64z cfsl number of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitro27l)de6 hic bgj)d6 uau8 yt+agen molecules contained 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 = 2000 psi masam j3rnao701 h)b6ke 3(yo (13,800 kPa) and at T = 259K How long will the cylinder last if the flo k3a)7(1yjem o 6aom03 ransbhw rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in asbpdx t27y fd6;vo*y 0dla m,t* d(4at bowl of liquid mercury at 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasoline at 0nl w4 o3ek2t,y$^{\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 eq4nkse4) cn df7g,r4j huator 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 j lg/cas9xoaot)4 5r.car 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, a 1j02jek ll1l5qhhj*4t ve)w jdopted 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 f5 ,ewwt lzgw byih;o (;,ps3: n56hrlxully charged, has a pressure of 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from the Earth:n:iv8tond; jv2k ks-y h:u e1 is $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspended against gravity by tennis balls throw :a8sa tys;57u(kp sryo+yolwi g r:2(n vertically upward at it. How ma rwl:852( iosy:aag p(usr;o ty7y+k sny 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-diameter (spherical) bubble of air from a depk4(+ntvb 0wea th of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air 40 tbe(kavw+nbehaves as a perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air onztwbsn8- 5wp kk;y5,popf -h 1 the following two days: b k p pp1hkt58sow;-nfz5-yw,
(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 inne 2 gtvr6w/wr sde:j tm1j;w/gfp/ ,8 the density of iron at STP, and when it is a solid deep pr:2//ed,;6j e wvt wr/gfj 8nwtm1 gsin 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, for an ideal gas at constant press)2tg;ei) g *ym -yqqvoure, the coefficient of voluqyvm)-gte2 go ) *yq;ime 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.

  In humid climates, people constantly dehumidify their cellars to phx-d k3z3c f,vrevent rot and mildew. If the cellar in a ho33, v-zfdxhckuse (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