Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the peq8gc9qukl- 5h2b(tpu*yn 3o zriodic table or h3b8 t*g 9 z(oycunlpq2uk-5qAppendix B.

Name several properties of materials that could be exploi)z 1fhyod7qyt oid8e-0q *yv5ted to make a thermomete deq8-1q70otozyfdy 5v)iyh* r.

Which is larger, 1 C-vs)q)eius :i tn + x9)rodv7k $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibr/qy:km:hb zra0 h;m) hium with system B, but B is not in thermal equilibrium with system C, wh:;my:hz0 bh haq/)rkm at can you say about the temperatures of A, B, and C?

A flat bimetallic strip coonr;qy z2( vkbb- (-rgnsists of aluminum riveted to a strip of iron. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hibo;zb-rr(2kyq( v- ng nt: 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 expansionn5 1 fuv u,op3ggy2n7prl4cc0 $\alpha$ 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 thert-szpe/2 uz z e3y mbx1-y/0vemostat 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 f-u2ev zbme t0y/ eszz /-x31pylow to touch both contact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at the ends often have a section in the shape ougy47p b, 83( kpep:nhhnq2mcajom- b7m1gh7f a U. Who m 3:yhn71q,8uggh7 be ppc4-(am2jm 7pbkn hy?

A flat, uniform cylinder of lead floats i4f6wvxk,n6mtr9s:b :g js m*j7 l -oybn mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glf/ k*erajnr6,ufl(2 tass thermometer is first placed in a hot tub of water, the mercury initially defrknlt, /6jue*(rf2 ascends a bit and then rises. Explain.

A glass container may break if one part of it is heated or cooljmzu)q -4bu v9jm5*r ded more rapidly than adjacent 45jvu9u*-)mzm rjdq b parts. Explain.

The principal virtue of Pyrex glass is n/auwgqr5(45:cnz rx3e kb/hthat its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the incren(e5 bx uhg5 rqr:wc 4n/za3/kased heat resistance of Pyrex.

Will a grandfather clock, u 59x,tu)q tg w(pb4jikg i)/iaccurate 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 budmyl *)1cta4c lge so badly the can will not stand up. What ha4d*1t)mc l aycs happened?

When a gas is rapidly compressed (say, by pushing down 1*fbj 46 pdw,9as bmfva piston), its temperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strikv*pwjab 1fm b f4,6ds9e the moving piston.

Will the buoyant force on an aluminum sphere submerged in water iik,ng*xoeb:cb./v7 7ac 2 afdncrease or decrease if the temperature is increased frov*7i2 .fkgnbac: ,d oe7/c axbm 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and the cr 4q ktl8jw(1relation between averc (j84ltkwq 1rage kinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinetic the s15g9pb1nks tory.

As you go higher in the Earth’s atmosphere, the ratio v.3cbx42aw qd of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers pd+uep c/vg 4nrwv ;jx):kk*: to the minimum speed an object must have to leave the Ekpn:)w4j rcp kvvg+x *u/;e:darth 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 mor zma)apr9u c7t(o m10v- +pfgue quickly than water at room temperature. What can you infer about the molecular (fao - t+vm ruzc0p9mu)71 agpproperties of one relative to the other?

Explain why a hot humid day is far more uncomfortable th w *.icbhwc tjxl.impxc p) +g(0k*a;- knx:f;an a hot dry day at the same temperaturwma. c*wbpx fpxkijgic l 0;(c +ht*k:-)n.x;e.

Is it possible to boil water atv .q+oio:x 6ol room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the bbayql8xy; d r61vkv11lt*3cair temperature is the same but the humidity is different. Which is more dense, the dry aiy;l *31q ydv6 11axlvrk8bbctr or the humid air at the same T? Explain.

Explain why it is dangerous to open the radi:kzb8s agjc4x*o yh2 1ator cap of an overheated automobile eb z hg a8jk:c2x1y*s4ongine.

Why does exhaled air appear as a little white clo8 , u2modpp bo/jv(f7hud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gra ijvgma9;: z jd:)ju/jm copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the zqm2 bip;/un vka7 ::l,d9w:j 1 gwgo+6ockk pnumber in apodzj ::ag/ kq,k k+ l9g6mniuc7wvpwb2:o ;1 silver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often cqtt 3x2ufjfi8) q3zix8(a j1taken to be 68°F. What is this on the Celsius scale?) iuxj3t8 caqfx1q( 2zft8ji3    $^{\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 andc5msk e fy7u4s 0 xxu0+o2s)aw lowest temperatures recorded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

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

  In an alcohol-in-glass thermome*nz 7r6h-w ay--ifdb(i ux b8nter, the alcohol column has length 11.82 cm at 0.0 -w*-7zd6ybnb in i rhau8 -fx($^{\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 oft a y;( s yy9:t8jbgqiw9yf5e3 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 approximately 3p ffqyk+bj9aa9duq1 nyu-( 8xr y33g 700 m tall. Estimate how mrf3 7xg ya 3quyb9k1n(9q yu+fad-8pjuch 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 th7l0.2w,iou c.afhhh ne rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in0ul7ohi .2hh,awf cn. 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 atby mwhtn8a5;e(m9 )ey 4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be its change in volume if it6,;ne 6dzmn7rj d9l sh 66j;dder7 nh9,lm nszis heated from 30 $^{\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 1k6e g0(+hcmd61yau 71 vk nyco00.0$^{\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 wvsq tv/aq w+b;-ex 5o7l f3m *n(sxi:zf6dn;s ater 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 made of iron*y(p;n.q,b 63ech f wfuhii(r. 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 g2hrly,a1gs:0h o3rodt 1ib5 vessel so it can expand in essentially one direction onlrty0o1h g5, gs3i hr:2 bod1lay, show that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in tj(ckwc z vk5ie2 0wvj:*z 0q4ox-kl()wnoy/ihe 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 yzq/) a.hziy-has coefficient of linear expay/ -hqiaz).zy nsion $\alpha$ 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 z6 mr9*lun p sr8(2u,zozn9tesolid, $\beta$ = 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 m9a4ze 3os ;1tm1lc2p:qjzbxfa2,ahb ade of brass and keeps perfect time at 1zpo ,3j:s ;2a 1t2zbqbxhca e4a9lf1m7 $^{\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 thermo0q( +obxra0h5d.xdb 1flzkp 6 meter has an inside diameter of 0.140 mm. The bulb has a volume of .k61dq+ a5 d (r bofxpzxhb0l00.255 $cm^3$ 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 cylindl93d37y7ee)ng2 d5g aqqrsdj rical wheel of radius 0.41 m is rotating about its axle on frictionless bearings ql3s)a2djeq79nder 3g d7 gy 5with 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 lengt8,r ,mwp up5ts+u.scsh when at 15°C. How much stress is required to keep it at this length if the suc, t5m ,pusw.sr +8ptemperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of clxu4 .+nje t1gross-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 20w/m 1pu 9sxs1x$^{\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 Kelvy djn ci9e3:atzbvh9q:08 w7qin 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 temperaturesagg dj 3,2wt) on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are ab/d-vovq xag* v:6-h 8kdel1er out 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 atmospheric4d8*o5 ljj) sz c(lobi9xo+vj pressure and a temperature of abol oc8 zb(+s5j oxjjid 9*vo)4lut 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 usipoemn (86 +d,adipid l 9gy83vng the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 4 m5x5mx8z:/d fcxy)j hptwmoy+ 7 a5s1ttm+okg 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 contay;g)gwgu3bms1q 9b pwy3e x(6ins 18.5 kg of nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gas is at f/j.ol:gyr*)3blyk+esx v p 310.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside a 35.0-L container holding 105.0 kg of vgkd zdae/ e74*nj+* rargon gas at 385 *ngdeza r7v e/ k+j4d*K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg of ;.t sbg q2 3bfx4gpn(f:-bgdb$O_2$ 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 +1cg ig8pexd.vgaqeiv iae+782a-s4 z* zli5heating the air inside the balloon, which makes it less dense than the air outside. Supposg 8+sl e74e+.di8apg1 x *5-2e iqag viczaizve 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 1 :l867gjrknf40vb qvw5 $^{\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.w15rw ae*6lri0 $^{\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 levelmea/ 5;m zhtqkw6 -ud9 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 moleculr(mc/4eym n:q es / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of watereae*wfomn 4p3xn-u h/9 a 27ar are there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) molrz.fd3mm pivav+mb6n 8u0k 3 -es,    $ \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 volum5m .;,97wpuq kedapm ne 5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L br qo (1(b+f p6w +f6 ij)nv(abzwrfusx,eath you inhale that were also )w(+wz(f njibqfov p+ur(fxas6, 6b1 in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an z9;yz v4 l6+33ymgqso nax :pizf6n a7 ibwq):oxygen molecule at STPa6)fbqn aswq4l + o9yzmpxny7 :gi 3vzz;36 i:?    $ \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 qf-q31t;e iojof the Sun at a temperature of q3to-q f;i1je about 6000 K.    m/s

  By what factor will thew t7b/l,6tzwszml*p,1 i mc9u rms speed of gas molecules increase if the temperature is increased from 07*zt9,tc1pl mw zw,su i/bl6m $^{\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 followinglhmx07x+ zffk m5-b 3btll9s8+ta2h :)zwxen speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 5fl8xhw 2mt)xb 0k3+mz s 9lh t7+:b-nfxaelz 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas at 20v qkp 36e5w0ge.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 whilerh m-5x pi41dg its volume is held constant, by what facp h54m 1idr-gxtor does $v_{rms}$ change?   

Show that the rms speed of molecules in++oi0pm2ao:)uomxzga uu.*7 uzx5q v 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 ratiogcm( garq40v 2 of their rms speeds is equal to the inverse ratio of the square roots of thea2 4g0vgrc(q mir molecular masses.

  What is the rms speed of nit uxyw0:/1jtqhwr ,zjv+c5md+ rogen molecules contained in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of an oxygen molibui-cb 9 ,o6vecule 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 distancef c 2/ tn91bdht6rd 1va7tz uk5s8(dte between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecul4rcgg( )1ioonar mass is 89 u in a living cel1(gn gr)ico o4l 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 caoxy .e3fw ontt 3+ke:.n 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 urajz qg4kr7 .a6unium, $^{235}$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 vi 1t90z6fkz qwhat 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 at(0v :sl, yxm*vdlode a-y 1zrj ol23a(m and the temperature is (a) 9 1rlejvx o3-yl om,dazv(:0 sld(2*ya0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a dayo*oo a odd))i1 when the temperatd)i*1 aooo od)ure is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boils at 957w7o kwtwyr, 0 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains iscb0 2slzo:7i npv7. tg 0.72 atm, estimate the temperature at which water z.7in0 plvo: s2c gt7bboils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressur:*y)m crm 0 ymj:;xgzre of water is 530 Pa and the;zc*yg xr mr:ym :jm)0 relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the temperature 5d o8pi- fv aw1kmq8/sis 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water3 j:dtmkt 4+uerz8 .fk is boiling atu z.:8t+e3j4k dfmrkt a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room )j ar0kbp2 wjv)m4b)vof 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 poinb,x m0kvua; f/m*bl 2bt of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time nee ihu5p1ar9a + .lmvr3bded for a glycine molecule (see Table 13–4) to diffuse a distance ofh1.rmv 3ra puba9+ li5 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 fromg(a -;38gw /esye kzzzhd69rovp2t xiej3:s5 the surface of insects to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and hagw8zrk 3doxe6- az3e st5e s2 ghiz(p/yj9:v;s 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 measu2dq-sgyw9 awj(5uo -k8l4i xr re 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) 5jgz4wud8aa been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal room tem:6 ni(3, rnekyflw8t aperature. How much error will be made in a recipe calling for 300 mL of cool water, if the wat8yi: nla63wf n ,rtke(er 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 initiall px )v 2+.g(vnl91 ,kyxupwdiey 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the cylinderxegn +dxw12)iv.,(v l9uy k pp?   

  Estimate the number of air molecules in a room ,fr*xboq(l/;5 okr 9-k fzfpiof length 6.5 m, width 3.1 m, and height 2.5 9rf5i-;/rk xo,opk*(lzq bf fm. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the densitdl3e4 kubot252h8/ konz o8h- - vuvwqy of matter is about one atom per $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best available vacuum taypa4 u 63sk75)smel iechniques is abo ap5 l37m6yu)es s4kiaut $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fillz kh;g lmr5 pxs+(ku;. *9s d7ble;vbys 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 the surface?.; klmhy(redup b;xzb;s9gks5*7l+v Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atm w/)zq 7vic 14kmj0epkosphere at a speed of about 40,000 km/h Molecules (assume nitrogen) kevwqm4z7p i0 )j1/k cstriking 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 s )3b4rkj pxjm 7)jj)q3er h pkg3c-.iis increased from 110$^{\circ} $C to 360$^{\circ} $C while the volume and the number of moles stay constant. By what factor does the pressure change? By what factor does $v_{rms}$ change?$\frac{P_2}{P_1}$ =    $\frac{(v_{rms})_2}{(v_{rms})_1}$ =   

  A house has a volume of 770mfi,me0 m4hgh,;4ad v cj wsv6-$^2$ (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 su7mv/xjpepn *,kqy18 s )8oslfrface of the Earth, estimate the total number of air molecules 7lqm)vfxy ko1,*p sns8p /e j8in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecul74n pzqq7w p0ja/xe(l dk)3dm es 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 hl 0mc6 jvu5rcjinacn5c;fuy; p 8* :9tas gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long wilc;8c0n:6py r9 i*unc5jmavl ;fj t5cul the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid mercury ap+13 jcwyp-1)yxn qn mt 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 4 bjfsll:h;obii 9w //m *shdg5 w,la0 dz)b(e0$^{\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 Earth4 csas0g/f e6m iki40r’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto gca/n05;h vyx 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,+iot( eay (j.su*2yvvh;8 a uimb92gn 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 b.gkjmko48bg,9o ,b2psskb9 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 Eart/w6so y5i t8osnux1+9zug9mnemsx71h 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 gravik25uecpl/ uc*a0r f-pty by tennis balls thrown vertically upward at it. How many tennis balls per second must-c*pa/0 u e 2l5kfcrup 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 (sph0mp80v i3f wpverical) 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 is f30pv0 8pmvw ithe bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the following two c w+5iyogb s/ xn-v*)edays: ibev ny/)g x+w5-co*s
(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, anki( x6r xdp(fl+kwm;v5k k.i2d when it is a solid deep in the Earth where thekw+k if (6d. xvk(k5xlr2p;m i 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 pressure 2+q av1.phc31suogvm , the gc312ahoq ms p1vu+.v coefficient 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.

  In humid climates, people con: o08gyio5t 6lgu barzlks, qk27 .kh:stantly dehumidify their cellars to prevent rot and k 2:0kr 7:.ukao,zitbg 5s gq8 l6olyhmildew. If the cellar 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