What happens to the work done when a jar o-vt (7e2jlfm tf orange juice is vigorously shaken?

When a hot object warms a cooler object, does temperature flow betw+hsc5ec5z z v6 r3vi7x7qnpf/ een them? Are the temperature changes of the two 5enxiz/cspc53rzv6v 7+h7qfobjects equal?

(a) If two objects of different temperatures are placed in contact, will heat (g bj .x aixzu3l)i c8(;.fmf (n.mwwmnaturally flow from the object with higher internal energy to tmmfigj ( l w m ziw.3bcua8xx(.).n;(fhe object with lower internal energy? (b) Is it possible for heat to flow even if the internal energies of the two objects are the same? Explain.

In warm regions where tropical plants grow but the temperature may drophq b 27t1aktj ;9n3 qj-bhlvs.76hfxk below freezi 9s2abk 7tt7q hn;j-kfxh1qlj3vh6b.ng a few times in the winter, the destruction of sensitive plants due to freezing can be reduced by watering them in the evening. Explain.

The specific heat of water is quite large. Explain why tzpa1 8:fbxvsk67b zx; his fact makes water particularly good for heating systems a6 bs8kfp1 ;xxz vz7:b(that is, hot-water radiators).

Why does water in a metal canteen stay u-0o chz l8s 7 3c)+ad9req/yvssomcc v* 1n6ucooler if the cloth jacket surrounding the canteen ism9+60s/ s3uo o avhquyez1*cl7v c cdc8rn)s- kept moist?

Explain why burns caused by steam on the skin are often more severe than burn z10*ga( .lx z:lba yewndl/l.s causedb wn/ lz*l zladx0:. y(.ael1g by water at 100 $^{\circ} C$ .

Explain why water cools (its temperature drops) when it evaporates, usinnl7sx ) u;zc231kb1 2okwue)ao4pc 4:cbx bef g the concepts of la)b 2seeo7p 1 x:axko1kbw fu4 b3cun4)2 ;lzcctent heat and internal energy.

Will potatoes cook faster if t)2uyow- i-yda j0 3dkehe water is boiling faster?

Does an ordinary electric fan cool the air? Why or why not?.nd 07j .naczln6eb)n If not, why use it?

Very high in the Earth’s atmosphere, the tempvpc ed *8 lznwu1wtjr 50bii9: /8pkp5erature can be 700 $^{\circ} C$ . Yet an animal there would freeze to death rather than roast. Explain.

Explorers on failed Arctic expeditions hav et1ev s58wf hj054irae survived by covering themselves with snow. Why would they do thah1eitjf e508savr 54wt?

Why is wet sand at the beach c cny0/-ne. jwxooler to walk on than dry sand?

If you hear that an obj* ej7ljw3dfg5hawtiq47 oy .3ect has “high heat content,” does that mean that its temperature is 7to jh.3wwail4ed 37fj* q5gy high? Explain.

When hot-air furnaces are used to heat a house, why is it important tl b4s7f-2 5wibzcpq9c4n jexcj-/e8uhat there be a vent for air to return to the furnacepe-l nci4zb b2 /u5weqs-8x c7cf9 jj4? What happens if this vent is blocked by a bookcase?

Ceiling fans are sometimes reversible, so that they drive9 1gp jvq7fdf7be q13k the air down in one season and pull i 7pjf31ge 9qvf1kd7bq t up in another season. Which way should you set the fan for summer? For winter?

Down sleeping bags and parkas are often specified a.c*2 eabttw6 cb9:nvv s so many inches or centimeters of loft, th6a2 ce*v9tnc wb.:vbte actual thickness of the garment when it is fluffed up. Explain.

Microprocessor chips have a “heat sink” glued on top that looks like a seriesp; n :qtb a/p9q5x8 che00crzu of fins. Why is it shapt0 b8rc9 :ne5pqu ch 0/zx;qaped like that?

Sea breezes are often encountered on sunny days at therhsnc,uw9 mc/fz k *+qg+vwy/w,.pm6 shore of a large body of water. Explain in light of the fact that the temperature of the land rises more rapidly than that of the nezf6+ ,y,ug9.crvk wpsqm// w+h ncm*warby water.

The floor of a house on a foundation under which the air jwr*lee:,7ia can flow is often cooler thaal ree:*,w j7in a floor that rests directly on the ground (such as a concrete slab foundation). Explain.

A 22 $^{\circ} C$ day is warm, while a swimming pool at $22\; ^{\circ}C$ feels cool. Why?

Explain why air temperature readxn0ynb kp3fy6o t:4 z)ings are always taken with the thermometer in the shade.3:oxyyf 4)n6p 0tbzk n

A premature baby in an incubator can be dang wmwyz+d dpe3;5a9i/xerously cooled even when the air temperature in the incubator is wi93ax/ywez;d pw5 md+arm. Explain.

Why is the liner of a thermos bottle:hd9+zn ,ayzvn*4e an-7 chbx silvered (Fig. 14–15), and why does it have a vacuum between4 n+n cneazhv- 9x :7dybh,za* its two walls?

Imagine you have a wal:ay bl kout32 vdpkkc4,v56j6 l that is very well insulated — it has a very high thermal resistance6vjbkd alyc up6, kk254o3:tv , $R_1$ Now you place a window in the wall that has a relatively low R-value, $R_2$ What has happened to the overall R-value of the wall plus window, compared to $R_1$ and $R_2$ [Hint: The temperature difference across the wall is still the same everywhere.]

Heat loss occurs through windows by the following procesui hg2om.m1ak 6k:, hj+zman5 ses: (1) ventilation around edges; (2) through the frame, particularly if it is metal; (3) through the glass panes; and (4) radiation. (a) For the first three, what is (are) the mechanism(s): conduction, convection, or radiation? (b) Heavy curtains reduce which of these heat losses? Exp 5uo.+m1h2km khj,agi:zn6 amlain in detail.

A piece of wood lying in the Sun absorbs more heat tdyecn 37son)m3 yhe 17han a piece of shiny metal. Yet the wood feels less hot cyhsey7d)13omn en7 3 than the metal when you pick it up. Explain.

The Earth cools off at night much more quickly9ib 6fjkvu5p2b *1 ktj when the weather is clear than whebf k6 kt92 vj*buji1p5n cloudy. Why?

An “emergency blanket” is a thin shiny (metal coated) plastic foil. q 63h0f:gj+rh8 v9yeyr :cerzExplain how it can help to keep an immo :ee08yh+3j69cvzrgq rh rfy:bile person warm.

Explain why cities situated by the ocean tend to have less e 0s; udhpd,zz1xtreme temperatures than inland cities at the same latis zup0d;zd,h1 tude.

  How much heat (in joules) is required to raise the b: :bm5uint/--dsnnt temperature of 30.0 kg of water from-t/tnu b5dnbsn -:im: 15 $^{\circ} C$ to 95 $^{\circ} C$ ?    $ \times10^{7 }\,J$

  To what temperature will 7700 J of heat raise 3.0 kg of water that is initial ohbg,kcjbll)eu*18 (h-9 x tkly at 10.8ok e,l9)-clxhuj gbh b t*(k10 $^{\circ} C$ ?    $^{\circ} C$

  An average active person consumes abouy;v n(l7 sa2u5c*axtdt 2500 Cal a day.
(a) What is this in joules?   $ \times10^{7 }\,J$
(b) What is this in kilowatt-hours?    kWh
(c) Your power company charges about a dime per kilowatt-hour. How much would your energy cost per day if you bought it from the power company? Could you feed yourself on this much money per day?    dollars per day

A British thermal unit (Btu) is a unit of heat in the British system of unifylj(cpzjne c ( r *q7*m*xb(2ts. One Btu is defined as the heat (*fc*mzxcj( *7l 2yne (pqbjrneeded to raise 1 lb of water by 1 F $^{\circ} $ . Show that
1Btu = 0.252kcal=1055J

  A water heater can generate vwmjlanj) 5: 2f2y,ot $32,000\,kJ/h$ How much water can it heat from 15 $^{\circ} C$ to 50 $^{\circ} C$ per hour?    kg/h

  A small immersion heat3g1rj . v)xzqher is rated at 350 W. Estimate how long it will take to heat a cup of soup (assgrh)j x1 3v.zqume this is 250 mL of water) from 20$^{\circ} C$ to 60$^{\circ} C$ .    min

  How many kilocalories are generated when the brakes are used to brqk gt:,; bmrxhbbh7-9ing a 1200-kg car to9bb; r:b7x,qg hht- mk rest from a speed of $95\,km/h$ ?    kcal

  An automobile cooling system holds 16 L of water. How much heat does it aalfv8 r1v)p l,bsorb if its temperal 18p )vvf,rlature rises from 20$^{\circ}C $ to 90$^{\circ} C$?    $ \times10^{ 6}\,J$

  What is the specific heat ofltvl,(.z:bs2 me pj :wa,j0ac a metal substance if 135 kJ of heat is needed to raisl, c:(ja2wmlj,0 b:aztv.e spe 5.1 kg of the metal from 18.0$^{\circ}C $ to 31.5$^{\circ} C$ ?    $J/kg\cdot\,C^{\circ} $

  Samples of copper, aluminum, anj 49dz* iuib.ld water experience the same temperature rise when they absorb the same amount of heat. What is the ratio of their masses? [Hintii b9l.d*u4 jz: See Table 14–1.]$m_{Cu}$ : $m_{Al}$ : $m_{H_2O}$ =    :    :   

  A 35-g glass thermometer reaq9v6 q61m9ku,sc 77 sto vj(tkjtvtn )ds 21.6$^{\circ} C$ before it is placed in 135 mL of water. When the water and thermometer come to equilibrium, the thermometer reads 39.2$^{\circ} C$ . What was the original temperature of the water?$T_{iH_2O}$ =    $^{\circ}C $

  What will be the equilibrium temperature when a 245ex 9vm dh+l*qglrn8l 3h* m j)g6tl6s:-g block of copper at 285$^{\circ}C $ is placed in a 145-g aluminum calorimeter cup containing 825 g of water at 12.0$^{\circ} C$ ? $T_{eq}$ =    $^{\circ} C$

  A hot iron horseshoecu xzn70pegh4ya *q a+grj,7- (mass = $0.4\,kg$) just forged (Fig. 14–16), is dropped into 1.35 L of water in a 0.30-kg iron pot initially at 20.0$^{\circ} C$ . If the final equilibrium temperature is 25.0$^{\circ} C$, estimate the initial temperature of the hot horseshoe.    $^{\circ} C$

  A 215-g sample of a substancl) 7+snrouwbym7 3 7mpe is heated to 330$^{\circ} C$ and then plunged into a 105-g aluminum calorimeter cup containing 165 g of water and a 17-g glass thermometer at 12.5$^{\circ} C$ . The final temperature is 35.0$^{\circ} C$ . What is the specific heat of the substance? (Assume no water boils away.)    $J/kg \cdot C^{\circ} $

  How long does it take a 7fd-b y9i)l. 1sphe gyp2sr )k750-W coffeepot to bring to a boil 0.75 L of water initially at 87i9ys. h2erpp)dyg f b- 1sl)k.0$^{\circ}C$? Assume that the part of the pot which is heated with the water is made of 360 g of aluminum, and that no water boils away. $\approx$    min (Round to the nearest integer)

  Estimate the Calorie content of 75 g of candy from the following measurements.-srv-3sk/b : o/w(8c9se dyi5iy9svv x a5pax A 15-g sample of the candy is allowed to dry before putting it in a bomb calorimeter. The aluminum bomb has a mass of 0.725 kg and is placed in 2.00 kg of water contained in an aluminum calorimeter cupic5/9so3 esy8vv/x:vsa59bkxyw pisr-(-ad of mass 0.624 kg. The initial temperature of the mixture is 15.0$^{\circ}C $ , and its temperature after ignition is 53.5$^{\circ} C$ .    Cal

  When a 290-g piece of iron 9xx+qzkx9,of at 180$^{\circ} C$ is placed in a 95-g aluminum calorimeter cup containing 250 g of glycerin at 10$^{\circ} C$ , the final temperature is observed to be 38$^{\circ}C $ . Estimate the specific heat of glycerin.    $J/kg \cdot C^{\circ} $

  The 1.20-kg head of a hammeccw8rrk 8e8v9 rf* ab uc9e:d3r has a speed of $6.5\,m/s$ just before it strikes a nail (Fig. 14–17) and is brought to rest. Estimate the temperature rise of a 14-g iron nail generated by 10 such hammer blows done in quick succession. Assume the nail absorbs all the energy.    $C^{\circ} $

  The heat capacity, C, of an object is defing n75z boclabx)(,wa5ed as the amount of heat needed to raise its temperat,7a5)lgw z( 5axbnb ocure by 1 $C^{\circ} $ . Thus, to raise the temperature by $\Delta\,T$ requires heat Q given by
$Q\,=\,C\,\Delta T$
(a) Write the heat capacity C in terms of the specific heat, c, of the material.
(b) What is the heat capacity of 1.0 kg of water?    $ \times10^{3 }\,J/C^{\circ}$
(c) Of 25 kg of water?   $ \times10^{ 5}\,J/C^{\circ}$

  How much heat is needed to mels +3/07u8k qq.scffps7 ccym nt 16.50 kg of silver that is initially at 20$^{\circ} C$?    $ \times10^{6 }\,J$

  A 0.095-kg aluminium sphere is dropped fj xch973dnc6 7 v0bdvzrom the roof of a 45-m-high building. If 65% of the thermal energy produced when it hits the ground is absorbed 9nc6v 3zbjdx 7 cd0vh7by the sphere, what is its temperature increase?    $C^{\circ}$

  During exercise, a person may give off 180 kcal of heat in 3y f-1s5 ;j/tgxk7zo ai0 min by evaporation of water fz iaost ; yfk-/7j51xgrom the skin. How much water has been lost?    kg

  If $2.80 \times10^{ 5}J$ of energy is supplied to a flask of liquid oxygen at -183$^{\circ} C$ how much oxygen can evaporate?    kg

  A 30-g ice cube at its melting point is dropped into anh13(gqc cj6zh insulated container of liquid nitrogen. How much nitrogen evaporates if it is at its boiling point of 77q (6cgz3chhj 1 K and has a latent heat of vaporization of $200\,kJ/kg$ Assume for simplicity that the specific heat of ice is a constant and is equal to its value near its melting point.    kg

  A cube of ice is taken from the free u(e-g9o fndtth i7p7mje /0o.zer at -8.5 $^{\circ} C$ and placed in a 95-g aluminum calorimeter filled with 310 g of water at room temperature of 20.0$^{\circ} C$. The final situation is observed to be all water at 17.0$^{\circ} C$. What was the mass of the ice cube?    $ \times10^{-3 }$ kg

  An iron boiler of mass 230 kejke0h6 n/te nb5m45zwj7jp1g contains 830 kg of water at 18$^{\circ} C$. A heater supplies energy at the rate of $52,000\,kJ/h$ How long does it take for the water
(a) to reach the boiling point,$\approx$    h (Round to one decimal place)
(b) to all have changed to steam?$\approx$    h (Round to the nearest integer)

  In a hot day’s race, a bicyclist consumes 8.0 L of water x)1ak y5 u1qma3es;fpover the span of four hours. Making the apex;)y113 sp qfka m5uaproximation that all of the cyclist’s energy goes into evaporating this water as sweat, how much energy in kcal did the rider use during the ride? (Since the efficiency of the rider is only about 20%, most of the energy consumed does go to heat, so our approximation is not far off.)    kcal

  What mass of steam atk(td / ..o:leaeuc9t.h g a:ar 100$^{\circ} C$ must be added to 1.00 kg of ice at 0$^{\circ} C$ to yield liquid water at 20$^{\circ} C$ ?    kg

  The specific heat of merc, tqt 2)b*ea g1ewan5zury is $138\,J/kg$$\cdot\,C$ Determine the latent heat of fusion of mercury using the following calorimeter data: 1.00 kg of solid Hg at its melting point of -3.9$^{\circ} C$ is placed in a 0.620-kg aluminum calorimeter with 0.400 kg of water at 12.80$^{\circ} C$ ; the resulting equilibrium temperature is 5.06$^{\circ} C$ .    $ \times10^{ 4}$ J/kg

  A 70-g bullet travelihn iebny,g iq,6.,h0lng at $250\,m/s$ penetrates a block of ice at 0$^{\circ} C$ and comes to rest within the ice. Assuming that the temperature of the bullet doesn’t change appreciably, how much ice is melted as a result of the collision?   g

  A 54.0-kg ice-skater movikuw6o7k+ i)c. *gybxp aox-7ing at $6.4\,m/s$ glides to a stop. Assuming the ice is at 0$^{\circ} C$ and that 50% of the heat generated by friction is absorbed by the ice, how much ice melts?    g

  At a crime scene, the forensic investigator notes that the 8.2-g lead kzd;6iwn /z-ubullet that was stopped in a doorframe apparently melted completely on impact. Assuming the bullet was fired at rnwd;u z/-6izkoom temperature (20$^{\circ} C$ ), what does the investigator calculate as the minimum muzzle velocity of the gun?    m/s

  One end of a 33-cm-long aluminum rod with a diamete.hlz vkcf( fc( m0yi,kb1kq3/r of 2.0 cm is kept at 460$^{\circ} C$ , and the other is immersed in water at 22$^{\circ} C$ . Calculate the heat conduction rate along the rod.    W

  Calculate the rate of heat flvzit0n sb y;3dn;22s+wybh2gq uf3v/ ow by conduction in Example 14–10, assuming that there are strong gusty winds and the externwy+v siy2n ;2 /h fdqnugz32;0s3 vbbtal temperature is -5$^{\circ} C$   $ \times10^{4 }$ W

  (a) How much power is5+: rpj1mg/rob f kr5p radiated by a tungsten sphere (emissivity $e\,=\,0.35$) of radius 22 cm at a temperature of 25$^{\circ} C$ ?    W
(b) If the sphere is enclosed in a room whose walls are kept at -5$^{\circ} C$ what is the net flow rate of energy out of the sphere?    W

  Heat conduction to skin.fanq y (ovl q2i3-9r6/xdpn3v Suppose 200 W of heat flows by conduction from the blood capillaries beneath the skin to the b92ylfrq 3vi(p3qva dno/n- x6ody’s surface area of $1.5\,m^2$ If the temperature difference is 0.50 $C^{\circ} $ , estimate the average distance of capillaries below the skin surface.    $ \times10^{-4 }$ m

  Two rooms, each a cube 4.0 m per side, share a 12-cm-k)ehc: eq z l 2kwa:yyk 380pu(9ycrm3thick brick wall. Because of a number of 100-W lightbuqcekyrcz29lm eyu: 0wa3kpyk (83) h:lbs in one room, the air is at 30$^{\circ} C$, while in the other room it is at 10$^{\circ}C $. How many of the 100-W bulbs are needed to maintain the temperature difference across the wall?    bulbs

  How long does it take the Sun to melt a block of ice ,g tji4ip;p3mat 0$^{\circ} C$ with a flat horizontal area $1.0\,m^2$ and thickness 1.0 cm? Assume that the Sun’s rays make an angle of 30$^{\circ} $ with the vertical and that the emissivity of ice is 0.050.    h

  A copper rod and an aluminum rod of l)x te ,l)u xuo,muge):yh3:n the same length and cross-sectional area are attached end to end (Fig. 14–18). The copper end is placed in a furnace maintained at a constant temperymg)3 oulue:xtl, u) n:h,x)e ature of 250$^{\circ} C$. The aluminum end is placed in an ice bath held at constant temperature of 0.0$^{\circ} C$ . Calculate the temperature at the point where the two rods are joined.    $^{\circ} C$

  (a) Using the solar constnv 7 c0r8+dkxws 4jtr6ant, estimate the rate at which the whole Earth receives e8 w0tc74jxd+6vnrskr nergy from the Sun.    $ \times10^{17 }$W
(b) Assume the Earth radiates an equal amount back into space (that is, the Earth is in equilibrium). Then, assuming the Earth is a perfect emitter ($e\,=\,1.0$) estimate its average surface temperature.    $^{\circ} C$

  A 100-W lightbulb generates 95 W of heat, which iih0qoe5c s49)dqxbv . s dissipated through a glass bulb that has a radius of 3.0 cm and is 1.0 mm thick. What is the difference in temperature between the inner and outer surfaces of the 0vidhc5 9 .qsq4 )eboxglass?   $^{\circ}C $

  Suppose the insulating qualities of the wall of a house cothuj ed a+,s(;me mainly from a 4.0-in. layer of brick and an R-19 layer of insulation, as shown in Fig. 14–19. What is;hud t (sjae,+ the total rate of heat loss through such a wall, if its total area is $240ft^2$ and the temperature difference across it is 12 $F^{\circ} $?    Btu/h

A double-glazed windezd )ckha;. 6(e(,fm yrq(bc row has two panes of glass separated by an air space, Fig. 14–20. (a) Show that the rate of heat flow through such a window by (fr (q)e yead;rhz,.b km(c6cconduction is given by
$\frac{Q}{t}$ = $\frac{A(T_2-T_1)}{l_2/k_1+l_2/k_2+l_3/k_3}$,
where $k_1$,$k_2$ and $k_3$ are the thermal conductivities for glass, air, and glass, respectively. (b) Generalize this expression for any number of materials placed next to one another.

  Approximately how long should it take 11.0 kg of ice 4;aprn/a.vee vct/y 7at 0$^{\circ}C $ to melt when it is placed in a carefully sealed Styrofoam ice chest of dimensions $25\,cm\times\,35\,cm\times\,55\,cm$ whose walls are 1.5 cm thick? Assume that the conductivity of Styrofoam is double that of air and that the outside temperature is 32$^{\circ} C$.    $ \times10^{4 }$s

  A soft-drink can contains abl-m 8 ua:01fkw nr:jyhz1w4rbout 0.20 kg of liquid at 5$^{\circ}C $. Drinking this liquid can actually consume some of the fat in the body, since energy is needed to warm the water to body temperature (37$^{\circ} C$). How many food Calories should the drink have so that it is in perfect balance with the heat needed to warm the liquid?    C

  If coal gives off $30\,MJ/kg$ when it is burned, how much coal would be needed to heat a house that requires $ 2.0\times10^{5 }\,MJ$ for the whole winter? Assume that 30% of the heat is lost up the chimney.    kg

  To get an idea of how much thermal energy is contained in the world’s;cz aj,p;+ 2fwdi m4jj oceans, estimate the heat liberated whe dcaw,jf 2mzj4;+j pi;n a cube of ocean water, 1 km on each side, is cooled by 1 K. (Approximate the ocean water as pure water for this estimate.)    $ \times10^{ 15}\,J$

  A 15-g lead bullet is tested by firing it into a fixed block of wood with a mf3cum(.h ocw+v a9) np,,iy jaass of 1.05 kg w.(v,c y 9po3uhiajn)am c,+f. The block and imbedded bullet together absorb all the heat generated. After thermal equilibrium has been reached, the system has a temperature rise measured as 0.020 $C^{\circ} $. Estimate the entering speed of the bullet.    m/s

  (a) Find the total power radiated into space f o6,vo hr+br )ol(,prby the Sun, assuming it to be a perfect emitter (6+ro ) bl,hv,pfoorrat $T\,=\,5500K$ The Sun’s radius is $7.0 \times10^{ 8}\,m$    $ \times10^{ 26}\,W$
(b) From this, determine the power per unit area arriving at the Earth, $1.5 \times10^{ 11}\,m$ away (Fig. 14–21).    $ \times10^{ 3}\,W/m^2$

  During light activity, a 70-kg pep cpj -7ll*t+mrson may generate $200kcal/h$ Assuming that 20% of this goes into useful work and the other 80% is converted to heat, calculate the temperature rise of the body after 1.00 h if none of this heat were transferred to the environment.    $C^{\circ} $

  A 340-kg marble boulder rolls off the top ofb k0 ip5mf pqcs+a;*)i a cliff and falls a vertical height of 140 m before striking the ground. Estimate the temperaturekq) s c5pfpba;0m+i* i rise of the rock if 50% of the heat generated remains in the rock.    $C^{\circ} $

  A 2.3-kg lead ball is dropped into am3n,z n0 hlril9eu,f 84f l 9rt;9fqkx 2.5-L insulated pail of water initially at 2;l8kfl,qf4n ehmt , r9l f9rxn9z iu030.0$^{\circ} C$. If the final temperature of the water–lead combination is 28.0$^{\circ} C$, what was the initial temperature of the lead ball?    $^{\circ}C $

  A mountain climber wears a goose down jacket 3.5 cm thick with tot dart8e p)xqlp;,;:q sal surface area aqs;xe8 lq pt,d :;)pr$1.2\,m^2$ The temperature at the surface of the clothing is -20$^{\circ}C $ and at the skin is 34$^{\circ} C$. Determine the rate of heat flow by conduction through the jacket
(a) assuming it is dry and the thermal conductivity k is that of down,    W
(b) assuming the jacket is wet, so k is that of water and the jacket has matted to 0.50 cm thickness.    W

  A marathon runner has an average metabolism rate of about 9e: .. dn2gf )e5epom ynvcox-$950\,kcal/h$ during a race. If the runner has a mass of 55 kg, estimate how much water she would lose to evaporation from the skin for a race that lasts 2.5 h.    kg

  Estimate the rate at which heat can be conductee cltwn 3vpr / lc nk+e5;9ui95jgu5z,eng+k )d from the interior of the body to the surface. Assume that the thickness of tissue is 4.0 cm, thw+;ren9ln/guz ,ke9 5 3 in)ckt vpjcu5l+e5gat the skin is at 34$^{\circ}C $ and the interior at 37$^{\circ}C $, and that the surface area is $1.5\,m^2$ Compare this to the measured value of about 230 W that must be dissipated by a person working lightly. This clearly shows the necessity of convective cooling by the blood.    W

  A house has well-insulated walls 17.5 cm thipe7g1 r j6 hmndulv on.h5p,.an.r2;x ck (assume conductivity of air) and areax.; h em5nld grnv p. hu12opn.,a6jr7 $410\,m^2$ a roof of wood 6.5 cm thick and area $280\,m^2$ and uncovered windows 0.65 cm thick and total area $33\,m^2$
(a) Assuming that heat is lost only by conduction, calculate the rate at which heat must be supplied to this house to maintain its inside temperature at 23$^{\circ}C $ if the outside temperature is -10$^{\circ} C$    $ \times10^{5 }$W
(b) If the house is initially at 10$^{\circ} C$, estimate how much heat must be supplied to raise the temperature to 23$^{\circ} C$ within 30 min. Assume that only the air needs to be heated and that its volume is $750\,m^3$    $ \times10^{ 8}$J
(c) If natural gas costs 0.080 dollars per kilogram and its heat of combustion is $ 5.4\times10^{7 }\,J/kg$ how much is the monthly cost to maintain the house as in part (a) for 24 h each day, assuming 90% of the heat produced is used to heat the house? Take the specific heat of air to be $0.24\,kcal/kg$$\cdot\,C$.    dollars

  A 15-g lead bullet trh, /5t.if pd/p 5dezs iv4joo8aveling at $220\,m/s$ passes through a thin wall and emerges at a speed of $160\,m/s$ If the bullet absorbs 50% of the heat generated, (a) what will be the temperature rise of the bullet? (b) If the bullet’s initial temperature was 20$^{\circ} C$, will any of the bullet melt, and if so, how much?    $C^{\circ} $

  A leaf of area $40\,cm^2$ and mass $ 4.5\times10^{-4 }\,kg$ directly faces the Sun on a clear day. The leaf has an emissivity of 0.85 and a specific heat of $0.80\,kcal/kg\,\cdot K$.
(a) Estimate the rate of rise of the leaf’s temperature.    $C^{\circ} $
(b) Calculate the temperature the leaf would reach if it lost all its heat by radiation to the surroundings at 20$^{\circ} $C.    $^{\circ}C $
(c) In what other ways can the heat be dissipated by the leaf?

  Using the result of part (a) in Problem 58, take into account radiation from tqcjkf0.b0-z/t4k4s th pr; y.5ymo ubhe leaf to calculate how mucs/jy.; 0z 0 4hbu.5otryp kbkft qmc4-h water must be transpired (evaporated) by the leaf per hour to maintain a temperature of 35$^{\circ} C$.    g/h

  An iron meteorite melts when it enters the u0r +b72kk83msdpxa90rmxv qEarth’s atmosphere. If its initial temper0msm7dxbu3p q r a8v9x0rk+k2ature was -125$^{\circ} C$ outside of Earth’s atmosphere, calculate the minimum velocity the meteorite must have had before it entered Earth’s atmosphere.    m/s

  The temperature within the Earth’mh g id a774qm9yt xt6qhxq://s crust increases about 1.0 C$^{\circ} $ for each 30 m of depth. The thermal conductivity of the crust is $0.80\,W/C^{\circ} \cdot\,m$
(a) Determine the heat transferred from the interior to the surface for the entire Earth in 1 day.    $ \times10^{18 }\,J$
(b) Compare this heat to the amount of energy incident on the Earth in 1 day due to radiation from the Sun.$Q_{Sun}$ =    $ \times10^{4 }\,Q_{interior}$

  In a typical game of squash (Fig. 14h j k+b hv5d.bxp:c-o5–22), two people hit a soft rubber ball at ad+j. x co:b5kbh-hpv5 wall until they are about to drop due to dehydration and exhaustion. Assume that the ball hits the wall at a velocity of $22\,m/s$ and bounces back with a velocity of $12\,m/s$ and that the kinetic energy lost in the process heats the ball. What will be the temperature increase of the ball after one bounce? (The specific heat of rubber is about $1200\,J/kg\,$$\cdot\,C$)    $C^{\circ} $

What will be the final result when6k4l:9ipgsmzpfb lxh)3 )f8 n equal masses of ice at 0$^{\circ} C$ and steam at 100$^{\circ}C $ are mixed together?

  In a cold environment, a person can lose heat by conduction and radi z)-lejfw ;t+wation at a rate of about 200 W. Estimate how long it would take for the body tempewz+ -jel)t;w frature to drop from 36.6$^{\circ} C$ to 35.6$^{\circ} C$ if metabolism were nearly to stop. Assume a mass of 70 kg. (See Table 14–1.)    s

  After a hot shower and dy5ci1hlu eji;8b.;*fpvxt 8 aishwashing, there is “no hot water” left in the 50-gal (185-L) water heater. This suggests that the tank has emptied and refilled with water at roug8 ;pxy;8ilj 1aei*fu. htb cv5hly 10$^{\circ} C$. (a) How much energy does it take to reheat the water to 50$^{\circ} C$? (b) How long would it take if the heater output is 9500 W?    s

  The temperature of the glass surhc2f17th jbah zp0: 2a0jui(-mhj7drface of a 60-W lightbulb is 65$^{\circ} C$ when the room temperature is 18$^{\circ} $C. Estimate the temperature of a 150-W lightbulb with a glass bulb the same size. Consider only radiation, and assume that 90% of the energy is emitted as heat.    $^{\circ} C$