Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodiiq .xpxt )u,t-3t4tlyie: r k+c table or Appendix3l:4 xtttr-,+)t xueqii pky . B.

Name several properties of m 6qczg18tc/c faterials that could be exploited to make a thermometer6/cgz q 8cft1c.

Which is larger, 1 C3hw pbxy0,j 5c $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system 9:g6,y0qc lvpz x- wgfB, but B is not in thermal equilibrium with system C, what can you sax9vgzcl 6-0 gpfywq,: y about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to 8/yi 2oc.nioj zl s5,la strip of iron. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hizli n8ly.i2o/sc 5 jo,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 4u sue3cgwip :0 bk-;3qpk9zmlinear 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 thermotc ;.j*qe he59*rp hdistat 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. Explaic ;eh* t.rd9he5 pqij*n how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed atc z4/bv;lnso/ the ends often have a section in the shape of ozvc;l/ sb4 n/a U. Why?

A flat, uniform cylinder of ler7tmp n55k* ls/ pzbx78 /wtviad floats in mercury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glat1 b3+m;hqryvn )k .kz6hdc )nss thermometer is first placed in a hot tub of water, the mercury initially descends a bit and then rish)y zn3qrh;nbv1m +t .)c k6kdes. Explain.

A glass container may break in 0/s914d5ltj*a:rvbk cat ,:veias-ar3 jv uf one part of it is heated or cooled more rapidly thaavv,c4 /3ka:*r1bd:tsaaire - stj l59j vnu0n adjacent parts. Explain.

The principal virtue of Pyrex f)rkrlv(z:ngj 3e4 (j;wy6bl*(vwp p yhq :j5 glass is that its coefficient of linear expansion is much smalyw j g z4rn:)vw:l*vypjj 3p (rlbqe(hkf56;(ler than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate at tv ijb,+ge7* uzpm2)j20 $^{\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 imgd0i0rel)m :1 )wt jqts bottom and top to bulge so badly the can will not stand up. W0:t) mmr d qle)gi01jwhat has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its tems t l8-wq+gkqp3/au*r perature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting whatak wpqr3g+ s-tu8*q/l happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum sphere submerged in water increase or decry,/gl2 gef8k ;ox5c erease if the tel2ko/ gr,5fec8 xegy;mperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic)e whds) :p..kyn0(yiymt0 o kjck ++p theory and the relation between average kinetic energy and to +ks di:khkm+.0)tc0ew j .y)npypy( he absolute temperature.

Explain in words how Gay-Lussac’s law follows from kin;fn7sb xla.d +qdb; 2setic theory.

As you go higher in the Earth’sod4 tk jvvj/ 5cj* at*:+3(td+ unsosd atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earq;vx2cik)4 iltn5p54hci bn 0 th refers to the minimum speed an object must have to leave the Earth and never return. The escape vellccni50k4 h2 pt; i4vnbx5iq)ocity 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 water at room temperature. W o 9esbzz/;l06cdv2t7mk kdh;hat can you infer about the molecular properties of one6; 0;dzecdmbkt7okl2 hvz/9s relative to the other?

Explain why a hot humid day is far more uncomfortable than a hot dry day a4olvj0 s 0eepc.-o ux:t the same temperateucp4js x o0o:e0lv.- ure.

Is it possible to boil wa a-ubuce+a5 96 ,erivb-i,waj ter at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days whslhk4 h7lac 7 uwk, :jnqp3)g2en the air temperature is the same but the humidity is different. Which is more dense, the dry air or the humid air at the same T? Explap47 s7wg2kn ,:)jqulhhlac3 k in.

Explain why it is dangerous to open the radia tul+ dhh9w1h08yq iy3tor cap of an overheated automobile enginedliy1wy+q3 h 0t uh8h9.

Why does exhaled air appear as a litk zd*cw,g;zhl f.7)hl6yp7cgow b1 v:tle white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-grxle9.d z,ms)h am copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atom xn86tlcn7qq3 s in a 26.5-gram gold ring compare to the number in a tc68x nlnqq3 7silver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often tak7hwheeejda8t nfj1 l19j0 f8(en to be 68°F. What is this on the Celsius scale?f8nhdeej j79(h 0fa18ljwe1t    $^{\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 temp x +yvt94g/v+4yygueyz-tl7 heratures 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 ther/e doyxyln9/sk(c1 s *mometer, the alcohol column has length 11.82 cm at 0.k y1*xlco s/s (de9/ny0 $^{\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 +f olfrxv. fpx2x(bg7 6o7(b;9ok..vvhk wmmf 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 300 yu6u afmm/, gx cnes)pg,: .x7m tall. Estimate xg g/cy,u)mu7sf : ,xamp n.e6how 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.nfe9ey. /fx) 5oqns7)l xkly hole are often used and the rivet is cooled (usually in dry ice) before it is placedoxee lf/y9lk.qy7s) fnxn.) 5 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 at 4 j n 6kgr3qi0w/$^{\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 c:l u* sy i71j3m s4cypdl2c:cbm in diameter. What will be its change in volume if it is heated fr7 2m u1j3::p iylsbcc ylscd4*om 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/:d) v/0 syyiyl oppbv3go /d+tl(vt0 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL of water at:u/h06ftgnt s 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. At 20w22 6+bbfmof 4x(ma77 ikpou l $^{\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 is v;:d9pb(0ajalb ra /n essentially one direction only,aba0 ;d(9rsl vpb :a/j show that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change d k+s8b zh)5wtin 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 lengt0uxrk d-a24rwe /mi*j1ad2s sh l and width w has coefficient of linear expans-ra4 2 /u1 xk0dsmjswaidr2*eion $\alpha$ 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 isotrge u5ksc/;: lhopic 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 bra da b3 l h3mpy:e1yrxb8slidpkr, m//eqe*(62ss and keeps perfect time at 17 m8(p:pdr1y/l 3em*bl 6 3 ehikqa/yxebs,r2 d $^{\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 insidelg 1*2g)mhdt3e) s j01ysedd g diameter of 0.140 mm. The bulb has a volume of 0.255g2*s hm0d dg1ljgt3 e )yd1se) $cm^3$ 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 w0:b8ksejrr6 ve :e ,ob2y wm/uheel of radius 0.41 m is rotating about its axle onbebe0k/jr6 w8 uo vy:m:res2, 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. How much stress is requiu79o3;c9vy opkgme u)red to keep it at this length if the temperature ; m37ego)kov99c uyp uincreases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional area 2e ncv p*nfhr.7s j+6m0.041$m^2$ 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 134.1tgru:g4p+mto va) z9 922 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 the Kd .5us ;ara mk3 ro .+7pt,)htdof;mthl8/nyo elvin 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 te9i :uk(wn(x 3v qeh3 3hxjsh t;doe..zmperature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Eay 3fo.sh ;x,upm4of(jrth 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 atmosphe p(h,ubs kjhm*05o 6fqric pressure and a temperature of abhk5osmq 0 *f6pjubh, (out 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. je h w 7wril,w4f11ji wb ik(:-0;miil   kg/$m^3$

  A storage tank contains 21.6 kg of nitrogeb-vsaf/f:e crb)oq3 at 7e((yn ($N_2$) 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 cont76nw(0igh4yh ixrfk7(7o kjnf o.1jlains 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 paa4x+gw d) s48xp59uuk 0lwnat 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 container holding 105.0tmc k8 u:4ejgn,*od1v kg of argon gas at 385 8gn d1:ock evjum*4, tK?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kgz*et83amkr p 0 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 insid l924 ta )jznngzako8z38we ,ue the balloon, which makes it less dense than tn3ztjone 2)8 ,laaw84 g9ukzzhe air outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled withs/ wdjsuukd62y-x+28 qe z/ 41pchopc air 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 :ak3wx d vuf36at 18.0 $^{\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 and 20.0 osf/g)d z exj; :l4,ip$^{\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 mop22 jk u rso4 10wf6lecqq5gb*lecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many 4ptsg esa*piv*9b1 g7 molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) mole szhj9 jz;4qcp2v)sk-)( hc hts,    $ \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 tn1yfh02 0kadk-6a b v5.1$ \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 efnjticavxa / elm+q9:x 6 ),bx)s57 oinhale that were also in the last breath Galileo to7f) x9jcnm, tq aiva6oxe:lx+b)5e/ s ok. [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 oxy0dzwnok v7by)knu; -0gen molecule at STP? zykvou;nwb00k7 d )-n    $ \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 nea:3 uxb1hd tpqc*ev2n9a9p w*g r the surface of the Sun at a temperature of about 6000 Kq* 9 gpv2ne*9 :ahwbtxcu p1d3.    m/s

  By what factor will the rms speed of gas molecules increase inqha/) zf+6dwy246dc nxo x7yf the temperature is increasehxa2dcfoz+y x 766 d4w)/ yqnnd 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, z3(c w5v iq( in(.ra6*nsytcv given in units of km/s: 6, 2, 4, 6, 0, 4, 1,i n(vcq 6*3si tn((avwr5zc.y 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules(h*cjq q-8gy s 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 i y)jm:z9fu*cvz1de.fa r) qe9ts volume is held constant, by what factorjf)9f 1zum:ayd).z*ere q 9 cv does $v_{rms}$ change?   

Show that the rms speed ofn d64b.h orm;h1+ kuyp) yv9;jucppp) 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 gasu)p60x+ekrrvv+( o wy p;- dao9ltp9nes at the same temperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecpd0v(+oyp n 9l;ue w9-r)t+ oakxp6rvular masses.

  What is the rms speed of nitrogen moleculeu 5wojrx(lpa k+ -wjsnqfb9v)- w;cyyd2 l1,4s 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 oxyge gu+ 4mi6mmyru ,yu/y;n 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 nitavsb0fyj ) +7grogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed o71e kce0l 0kaovxe); 0pjm m0wf an amino acid whose molecular mass is 89 u in a living cell at 7ko;1mame le0kpj0x ) cv0e 0w37 $^{\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 written Pq-/9iiyjt5c61q/ m t :wze opd = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uransiz 6os nv37:tiq5 y;nium, $^{235}$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 pr4y/sz/c 1zyeb+tcwte*s2j sz cld1 9 .essure, 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 wfg0z lze ;fjk+;c8*jl hen the pressure is 0.01 atm and the temperature is (a)f+0z8*zjl jek;l;gc f 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity cju7 ./mkzxj8 pkx15i is 50% on a day when the temperature isx7xu 1/kmjj8.pz k 5ci 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place whe67mmp c4to w;hre water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a parti0qcgt;f.a (kbi : dt/kcular place in the mountains is 0.72 atm, estimate the temperad0t(;.q bck /t:k fgaiture at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 530 Pa bwa2lc-s( o4ey )s;rnx05wa land ta )en-wsb(04rlac x sol;5 2ywhe relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the tempelt ub+1,bznp+e nz5s*rature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure ins8cf)ba-h 93:;y4ga n vzqz; nlais 0eiide a pressure cooker if the water is boiling at a temperature of 120 -084ycqe;zfalni)9v3hi:z as a gb ;n $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of u grc(qv7x9lb1,6 /1 daecifn 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 d qlopep/zp .6*ew point of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine molecule (see Tabl.yf. (4fxrtp(g3yiu (yj t f;r;6alwpe 13–4) to diffuse a distance x6 r.;yp;f3u af 4(ftiy(l .jrgyp( wtof 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 surfa,rbpnwd8a-+ bs-;aof ce of insects to the interior through tiny tubes called tracheae. An average tr-f8bb-+oa rda,; snpw achea is about 2 mm long and has cross-sectional area of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure has been calibrated o( n1m gu nj7x5* yv8ffxmj,x: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 calb ogyh;jgxv ,:el( +,b7xi4ilibrated 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 nor((oaeknvo8 i5 mal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the watero5ea ivo8k((n 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 mali;p3*8 j0le d z swia-ku56tnny balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains ilp0we azu-*3j t ;5n8l6di ksin the cylinder?   

  Estimate the number of air molecules in a room of length 6.zee; vpocn4m* d7.74aqjyybf. bfq/+5 m, width 3.1 m, and height 2.5 m. Assume the dbf va+/ y7qjenc*z;fqo.4 emp4 by.7temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about c9 5py 8wn)dvuhtu26 pone 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 s fye fz)w7bs19i0h *yh : .wu;uqsu+athe best available vacuum techniques is about1u.)7q; ffs*i+ysuesu9z0 bhwwayh: $10^{-12} N/m^2$ 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 omz(1yvqtw1otf p 4 i11f 5.5 L when 10 m below the surface, to what volumeof(t1yi1m q4z wpt1 v1 would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s az:kpr.;l0ktq tmosphere at a speed of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze ukqp0 k:l;z. rtpon reentry.)    K

  The temperature of an i4ar6dsta 6lf706f fy5 s( lazhdeal gas is increased from 110$^{\circ} $C to 360$^{\circ} $C while the volume and the number of moles stay constant. By what factor does the pressure change? By what factor does $v_{rms}$ change?$\frac{P_2}{P_1}$ =    $\frac{(v_{rms})_2}{(v_{rms})_1}$ =   

  A house has a volume of 77+ub:c. ppgy;b,e ht3g0m$^2$ (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 sur :)ok wmzxgu2ka);lx3 rft95kface of the Earth, estimate the total numouar9gz)2k x)5kx3kl;:wt mf ber of air molecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen m) tzm5mul +ak.q+vn5rolecules 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 ha.a inn4s4s;k iwb m,8ys gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the bw k8ms a4;y4s in,.niflow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in 05l-xe d-)dp sn70luwh. ltc gp/i s3ha 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 pukfa 8g:u9kwx9e-j + at 0$^{\circ} $C is 0.68$ \times10^{3 }kg/m^3$ What is the density on a hot day, when the temperature is 38$^{\circ} $C?    kg/$m^3$
What is the percentage change?    %

  If a steel band were to fit snugly around the Earth’s equadr/cr;ho 6,3jz.hsa /jq vts/h t(ii6 tor 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 oj(s5j 7s -jlpcd+/8cexg.d flaa )ci:nto 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, adopted in thep .srt q qa7sd5d645y cv. jm.ak5-sqz 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully c c)*ueoy6j0 ka4qd9mpharged, 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 Ej o h+08a) y5i 0mno1rvlprvxp f+-yc3arth 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 suspenyhtl*:w 27okat4;a ru)g 2ty kded against gravity by tennis balls thrown vertically upw2 ):k;2 htaoy7 ktt aylgrw4*uard at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubble of air from ak4h 98/l4go8 ;ld h)zvqlzajw depth of 14.0 m in a lake. Assume the temperature is constant at9 lwzahvk84;q8j zol/ gdhl) 4 298 K, and the air behaves as a perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air on the fol(pivpg(zn (v tg)fu) )lowing two days: f( gtinu gz)pv (p())v
(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 denspvof9 kn,/6 ogity of iron at STP, and when it is a solid f 9vkog ,onp6/deep in 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 atsr+ t(9h/aws7 l7 rjf l4wg1af constant pressure, the coefficient of volume expansion is equal togwas4alsw +9hfjrr7l(/7 ft1 $\beta$ = 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 dehumidif7 j3,0 qroh0-vcjvmiqy their cellars to prevent rot and mildew. If the cellar in a house (kecq3o0r, 7vj iqv0hjm-pt 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