Why is the depth of field greater, and the image sharper, when a camera l. e8-ots kx:yn4prb +zens is “stoppne+ox pbkr-t4: 8zsy.ed down” to a larger f-number? Ignore diffraction.

Describe how diffraction affects the statemid 0m* w9;nwo,fb7gmja 2 (rqnent that the depth of field is greater and the image sharper when a camemiajnqo0g7,w2*f n (9d ;wmb rra lens is “stopped down” to a larger f-number.

Why must a camera lens be moved fartherok :6gyrfw1r*,* fam g:nee e) from the film to focus on a closer objecawyfn ,o)6 *1km*g:errg e:fe t?

Why are bifocals needed mainly by older persons and not generalldzjo+1e hrrj y- 8*ms*y by younger peoplre j j*1rsdmy8+hz* o-e?

  Will a nearsighted person who wears corrective lenses in her gla altiw5bb ngo+h jz m1*:q9x3,sses be able to see cleai 9 ,bjqh*:1zgt mx3b+5lwa onrly underwater when wearing those glasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether a viq5h+o .wm hhj/3+xiperson is nearsighted or farsighted by looking at the width of the face through their glasses. If the person’s face appears narrower through the glasses (Fig. Below), is thjw+o+mhvqx5ih/ 3i. he person farsighted or nearsighted?

In attempting to discer47wdn ) dof(.o nso/-r okxyb8n distant details, people will sometimes squint. Why does thy odd wxnofb)8n4 s 7/.-rook(is help?

Is the image formed on 9 p vw/9ez1z0xbc6bok the retina of the human eye upright or inverted? Discuss thv9eozbxb6 wkp9zc0/1e implications of this for our perception of objects.

The human eye is much like a camera — yet, when a camera shutter is lfr 54bu ,m(aan.i,8k1i:8cupsce evl eft open and the camera is moved, the image will be blurred; but when you move your head with your,.r 8acbukilica,n4(p:ue fv ems581 eyes open, you still see clearly. Explain.

  Reading glasses use conlq8*s08 6w k7gujdlaa verging lenses. A simple magnifier is also a converging lens. Are reading glaskq86 w70l8dasul g ja*ses therefore magnifiers? ----待选择----yesno  Discuss the similarities and differences between converging lenses as used for these two different purposes.

Inexpensive microscopes for children’s use usually produav/9 a3jzu k+0hzgg0b l04mh zce images that are colored a30zj4b h+ghal90 u0kva zgzm/ t the edges. Why?

Spherical aberration in a thin lens is minimize3 :scu9uniia* d if rays are bent equally by the two surfaces. If a planoconvex lens is used to form a real image of an object at infinity, which surface should face the object? Use ray dias*ia 3 :nui9ucgrams to show why.

Which aberrations present in a simple lens are not present (or ammrc l 2bjia8h:612v( kqia ,jre greatly reduced) in the hu (8 ,12jikqrvh:ibc62l mma jaman eye?

Explain why chromatic aberration occurs for thin lenses- ilyy(c0h* ki but not for mirrors.

  By what factor can you improve resolutio7ad yrvyj 2t l6m-lj5eiv/ *n5n, other things being equal, if you use blue lna e 5j r6/yy dj*t2lv7-vil5might ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two adv;+erbbd c o6q6j8i ih y;+f05heyi (cgantages for the use of large reflecting mirrors in astronomical telesc iy+ g(h+h6b 6 eio;fdjq8c ;5ie0brcyopes.

Which color of visible light would give the best rznl ,s-u z 6uhk7o;j.fesolution in a microscope? Expo ,-hnjfuk.7zlz ;6 uslain.

  Atoms have diameters of abhrl z 7w zj1*udzqd45hn jk,9 ;m/7kjpout $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stops ra l.iy 6v,krk9s(cf)ht nging from $f/1.4$ to $f/22$. What is the corresponding range of lens diaphragm diameters?    $\mathrm{mm}\leq D\leq$    $\mathrm{mm}$

  A television camera lehwje+du8z/ s)fm+x:x*oj uh 3ns has a 14-$cm$ focal length and a lens diameter of 6.0 $cm$. What is its $f$-number? $f$/  

  A light meter reports that a camera setdm/u:rovo9;q ting of $\frac{1}{250}\,s$ at $f/5.6$ will give a correct exposure. But the photographer wishes to use $f/11$ to increase the depth of field. What should the shutter speed be?$t_2$ = 1/   s

  A properly exposed photograph is taktyj* +sh-em(mh e5(a yen at $f/16$ and $\frac{1}{60}\,s$ What lens opening would be required if the shutter speed were $\frac{1}{1000}\,s$? $f$/  

  If an $f$ = 135-mm telephoto lens is designed to cover object distances from 1.2 m to $\infty $, over what distance must the lens move relative to the plane of the film?    mm

  A 200-mm-focal-length lens can be adjusted so that it is 200.0 mm tz 6 l u/02/eljecby/azdja 04co 206.0 mm from the film. For what range of object distances can it be 6du/2cjzc0aye 0 bz/l4alje/adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photograph a 28-mtall tree from a distance of 5d)cfd4h53atw zz 5a-r,a2j gx8 m. What focal-length lens should be used if the image iszgcwj a32,a-a4)d tr zfh 5x5d to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiny pinhole instead of a lens. eo1p;h r2qo vdaqdeq/3 v.6*g8yf a+kShow, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particuv oayhpq d1f8gqr*d6 a+ /3oqvek;e.2lar, consider two point objects 2.0 $cm$ apart that are 1.0 m from a 1.0-mm-diameter pinhole. Show that on a piece of film 7.0 $cm$ behind the pinhole the two objects produce two separate circles that do not overlap.

  Suppose that a correct expose9o )plna*n5b0 a 2dnxure is $\frac{1}{250}\,s$ at $f/11$ Under the same conditions, what exposure time would be needed for a pinhole camera (Problem 8) if the pinhole diameter is 1.0 mm and the film is 7.0 $cm$ from the hole? $t_2$ = 1/   s

  A human eyeball is about 2.0y mpqh)zk,(ol- 3h 2qg $cm$ long, and the pupil has a maximum diameter of about 8.0 mm. What is the “speed” of this lens? $ f-stop$ = f/  

  If the nearsighted person in Example 25–6 wore contact lenses corrected dpj-43v santni fx:* 5for the far:nfna s4t vpd-x j35*i point $(=\,\infty)$ show that the near point would be 41 $cm$. (Would glasses be better in this case?) glasses would be  ----待选择----betterworse 

  Reading glasses of what power are needed for a person whose nea(1uzfzvf ai;z,4zzn6r point is 115 $cm$, so that he can read a computer screen at 55 $cm$? Assume a lens–eye distance of 1.8 $cm$.+    D

  A person has a far point o)apx 3ltf9bg2kl2 )g wf 14 $cm$. What power glasses would correct this vision if the glasses were placed 2.0 $cm$ from the eye?    What power contact lenses, placed on the eye, would the person need?   

  A person struggles to read by holding a book at arm’s length, a distance d1(3xl 5bwa9ia nvhh ;43flrb of 45 $cm$ away (= near point). What power of reading glasses should be prescribed for him, assuming they will be placed 2.0 $cm$ from the eye and he wants to read at the normal near point of 25 $cm$? +    D

  A person’s left eye is corrected by u+k ifsv u)l+5lt zv:h2:.pboa $-3.50-diopter$ lens, 2.0 $cm$ from the eye.
(a) Is this person’s left eye near- or farsighted?  ----待选择----nearsightedfarsighted 
(b) What is this eye’s far point without glasses?    cm

  A person’s right eye can see objects clearly only if they are betwcsgv/: dc1 o,1ecx,hteen 25 $cm$ and 75 $cm$ away.
(a) What power of contact lens is required so that objects far away are sharp? -    D
(b) What will be the near point with the lens in place?    cm

  About how much longer is the nearsighted eye inptwix 8*zgfu e*jtb(f.)qt z5-fj ,* x Example 25–6 than the 2.0 $cm$ of a normal eye?    cm

  One lens of a nearsighted person’s eyeglassesu-+ 5ve t+(vt un6k8,zr x:prpq7sk iw has a focal length of $-22.0 \, cm$ and the lens is 1.8 $cm$ from the eye. If the person switches to contact lenses that are placed directly on the eye, what should be the focal length of the corresponding contact lens?    cm

  What is the focal lenghxqrf,.-az2e si (h jop6q 9a)th of the eye–lens system when viewing an object
(a) at infinity,    cm
(b) 33 $cm$ from the eye? Assume that the lens–retina distance is 2.0 $cm$.   cm

  A nearsighted person has near an;v:x n1ui1vjho +n ,utd far points of 10.0 and 20.0 $cm$, respectively. If she puts on contact lenses with power $P\,=\,-4.00D$, what are her new near and far points?
near point    cm
far point    cm

  What is the magnification of a lens used with a relaxed ehr +,9ekn j.ahye if its focal length is e.h+har,nkj9 12 $cm$? =    $\times$

  What is the focal length of a magnifyingjoevv 9u: rzmd/ 89by) glass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated at xqufm5s-7zj j1r)ur *$2.5\times$for a normal eye focusing on an image at the near point.
(a) What is its focal length?    cm
(b) What is its focal length if the $2.5\times$ refers to a relaxed eye?    cm

  Sherlock Holmes is using niq ;8ritu wdu(44ma/ a 9.00-$cm$-focal-length lens as his magnifying glass. To obtain maximum magnification, where must the object be placed (assume a normal eye), and what will be the magnification?
$d_o$ =    cm from the lens
M =    $\times$

  A 3.30-mm-wide beetle is viewed with a 9.j.3w; i,dkwegf l9r7j 50-$cm$-focal-length lens. A normal eye views the image at its near point. Calculate
(a) the angular magnification, =    $\times$
(b) the width of the image,    mm
(c) the object distance from the lens.    cm from the lens

  A small insect is placed 5.2ymia fdva **/55 $cm$ from a $+6.00-$cm$-focal-length$ lens. Calculate
(a) the position of the image,    cm
(b) the angular magnification. =    $\times$

  A magnifying glass with a focal length of 8.5 kzq4:g8*szyg $cm$ is used to read print placed at a distance of 7.5 $cm$. Calculate
(a) the position of the image;    cm
(b) the angular magnification. =    $\times$

  A magnifying glass is r9qhthiuk0y r3 . te8r,ated at $3.0\times$ for a normal eye that is relaxed. What would be the magnification of this lens for a relaxed eye whose near point is
(a) 55 $cm$, =    $\times$
(b) 16 $cm$? Explain the differences. =    $\times$

  What is the magnification of an astronomical telescopuhbp ,jua.0siub y uf4wx.hgy1-o99:e whose objective lens has u hpi4h,bgyj u 1-yo.u:.wxb0 9sua9fa focal length of 76 $cm$ and whose eyepiece has a focal length of 2.8 $cm$? What is the overall length of the telescope when adjusted for a relaxed eye?
M =    $\times$
L =    $\times$

  The overall magnification of an astro (iw yfh-r5w yerk7i9t7 n.5*nbi4lr enomical telescope is desired to be 25$\times$. If an objective of 78$-cm$ focal length is used,
what must be the focal length of the eyepiece? $f_e$ =    cm
What is the overall length of the telescope when adjusted for use by the relaxed eye? L =    cm

  An 8.0$\times$ binocular has 2.8$-$cm$-focal-length$ eyepieces. What is the focal length of the objective lenses?    cm

  An astronomical telescope has an objective with focal levl/d;)).vfo m2g o tcnngth 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has its t z.t6rpgxa91v,/exdt wo lenses spaced 75.2 $cm$ apart. If the objective lens has a focal length of 74.5 $cm$, what is the magnification of this telescope? Assume a relaxed eye. =    $\times$

  A Galilean telescope adjusted for q /2 v(ily8ajik4. pusa relaxed eye is 32.8 $cm$ long. If the objective lens has a focal length of 36.0 $cm$, what is the magnification? =    $\times$

  What is the magnifying powerr 3kgt/ k57 oof/wkpp7 of an astronomical telescope using a reflecting mirror who7g/t5okpo3/wr7k fpk se radius of curvature is 6.0 $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appears to be magnified 12bfzi dg)y *+r39aba( c0$\times$ by a reflecting astronomical telescope with an eyepiece having a focal length of 3.2 $cm$. What are the focal length and radius of curvature of the main (objective) mirror? M =    m r =    m

  A 170$\times$ astronomical telescope is adjusted for a relaxed eye when the two lenses are 1.25 m apart. What is the focal length of each lens?
$f_e$ =    mm
$f_o$ =    m

  A reflecting telescope (Fig. Below) has a radius of iv8m zb98jcwn)r0rn; rmk0z) curvature of 3.0 m for its objective mirrozk) 8r0v;rmnb9nj rm 0)z 8iwcr and a radius of curvature of $-1.50m$ for its eyepiece mirror. If the distance between the two mirrors is 0.90 m, how far in front of the eyepiece should you place the photographic film to record the image of a star? $d_{2i}$ =    m

  A microscope uses an eyepiece izr. i1 /pdmt.with a focal length of 1.40 $cm$. Using a normal eye with a final image at infinity, the tube length is 17.5 $cm$ and the focal length of the objective lens is 0.65 $cm$. What is the magnification of the microscope? =    $\times$

  A 620 $\times$ microscope uses a 0.40-$cm$-focal-length objective lens. If the tube length is 17.5 $cm$, what is the focal length of the eyepiece? Assume a normal eye and that the final image is at infinity. $f_e$ =    cm

  A 17-$cm$-long microscope has an eyepiece with a focal length of 2.5 $cm$ and an objective with a focal length of 0.28 $cm$. What is the approximate magnification?    $times$

  A microscope has a 12c*mirkmp*/ i741 re qy.0$times$ eyepiece and a 59.0$times$ objective lens 20.0 $cm$ apart. Calculate
(a) the total magnification,    $times$
(b) the focal length of each lens, $f_e$ =    cm $f_o$ =    cm
(c) where the object must be for a normal relaxed eye to see it in focus. $d_o$ =    cm

  A microscope has a 1.8-/pufnl q f(cj32(spip5y/ wvb c:i *e.$cm$-focal-length eyepiece and a 0.80-$cm$ objective lens. Assuming a relaxed normal eye, calculate
(a) the position of the object if the distance between the lenses is 16.0 $cm$, $d_{oo}$ =    cm
(b) the total magnification.    $times$

  Repeat Problem 61 ass)feb( g2ek 17f8sjg iauming that the final image is located 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound microscope has a fd y;5oyqz:n zw5 6/nruocal length of 2.70 $cm$, and the objective lens has $f=0.740\mathrm{~cm}$. If an object is placed 0.790 $cm$ from the objective lens, calculate
(a) the distance between the lenses when the microscope is adjusted for a relaxed eye, $l$ =    cm
(b) the total magnification.    $\times$

  An achromatic lens isl ;yn6o 3lzwzjus6 0xn+ zpd3; made of two very thin lenses, placed in contact, that have 6jlw6lp 03zzz so+d;xu nn3;y focal lengths of $f_1=-28\mathrm{~cm}$ and $f_2=+23\mathrm{~$cm$}.$
(a) Is the combination converging or diverging?  ----待选择----convergingdiverging 
(b) What is the net focal length?    m

  Let’s examine spherical aberration in a particular situation. A planoconv) c+wiikf :n hb9l;y7zpc l*0pex lens of inpili+)kflc*wz 79p :chb 0;yndex of refraction 1.50 and radius of curvature $R=12.0\mathrm{~$cm$}$ is shown in (Fig. Below). Consider an incoming ray parallel to the principal axis and a height h above it as shown. Determine the distance d, from the flat face of the lens, to where this ray crosses the principal axis if
(a) $h=1.0\mathrm{~$cm$},$ $d_1$ =    cm
(b) $h=6.0\mathrm{~$cm$},$ $d_2$ =    cm
(c) How far apart are these “focal points”? $\Delta d$ =    cm
(d) What is the radius of the “circle of least confusion” produced by the $h=6.0-\mathrm{~$cm$},$ ray at the “focal point” for $h=1.0\mathrm{~$cm$},$? r =    cm

  What is the angular resol+tz1ro,;mipbpnc w , k)3h;cy ution limit (degrees) set by diffraction for the 100-in. (opb;ic p,;zw1 ck3 t+nyh )m,r254-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to construct a d0eqmhl bj--cfa2 30ftelescope that can resolve features 7.0 $km$ across on the Moon, 384,000 $km$ away. You have a 2.0-$m$-focal-length objective lens whose diameter is 11.0 $cm$.
What focal-length eyepiece is needed if your eye can resolve objects 0.10 $mm$ apart at a distance of 25 $cm$? $f_e$ =    cm
What is the resolution limit (radians) set by the size of the objective lens (that is, by diffraction)?
Use $\lambda=550\mathrm{~nm.}$ $\theta$   $ \times10^{ -6}\;rad$

  The normal lens on a 35-mm camera jaxt5)yn 4h*,axek0rhas a focal length of 50.0 $mm$. Its aperture diameter varies from a maximum of 25 $mm$ $(f/2)$ to a minimum of 3.0 mm $(f/16)$. Determine the resolution limit set by diffraction for $f/2$ and $f/16$. Specify as the number of lines per millimeter resolved on the film. Take $\lambda=550\mathrm{~nm.}$
For $\frac{f}{2}$ we have $\frac{1}{RP_2}$ =    lines/mm
For $\frac{f}{16}$ we have $\frac{1}{RP_2}$ =    lines/mm

  Two stars 15 light-years away are barely resolved by q4dja t y0la/;a 55-$cm$ (mirror diameter) telescope. How far apart are the stars? Assume $\lambda=550\mathrm{~nm.}$ and that the resolution is limited by diffraction.   $ \times10^{11 }\;m$

  (a) How far away can a human eye distinguish two car-dcv(zg+)m8lpze efmy7 tf:/ headlights 2.0 $m$ apart? Consider only diffraction effects and assume an eye pupil diameter of 5.0 $mm$ and a wavelength of 550 $nm$.
L =    km
(b) What is the minimum angular separation an eye could resolve when viewing two stars, considering only diffraction effects? In reality, it is about of arc. Why is it not equal to your answer in (b)? $\theta$ =    $\times 10^{-3}$ $^{\circ}$

  The Earth and Moon ar/mcauzhdif *-(:pb70mnceb z5)p n ;se separated by about $400\times10^6\mathrm{~m.}$ When Mars is $8\times10^{10}\mathrm{~m}$ from Earth, could a person standing on Mars resolve the Earth and its Moon as two separate objects without a telescope? Assume a pupil diameter of 5 $mm$ and $\lambda=550\mathrm{~nm}.$  ----待选择----yesno 

  X-rays of wavelength 0.133 nm fall on a crystal whose atoms, lyin56lnd9o xuoj ;*g8 udng in planes, are spaced 0.xuno g96uon* d;j5 dl8280 $nm$ apart. At what angle \phi (relative to the surface, Fig. Below) must the X-rays be directed if the first diffraction maximum is to be observed? $\phi $ =    $^{\circ}\,$

  X-rays of wavelength 0.0973 nm are directeu);9kq )8v abpu 5/*3hchrslwljk qb 5d at an unknown crystal. The second diffraction maximum is recorded when the X-rays are directed at an angle uhb)lw a* kkj)rqhv53lu8c/b p;sq 59of $\mathrm{23.4°}$ relative to the crystal surface. What is the spacing between crystal planes? d =    nm

  First-order Bragg diffraction is o4lpyhy z wvlb:h)58j5 bserved at $\mathrm{25.2°}$ related to the crystal surface, with spacing between atoms of 0.24 $nm$.
(a) At what angle will second order be observed? $\phi_2 $=    $^{\circ}\,$
(b) What is the wavelength of the X-rays? $\lambda $ =    nm

  (a) Suppose for a conventional X-ray image that the X-ray beam consists of xtq l48 +w,3ehkkkq /dparallel rays. What would be the magnification of the image? a the magnificationkkd q4k,8x/h lw +qe3t is   
(b) Suppose, instead, the X-rays come from a point source (as in Fig. Below) that is 15 $cm$ in front of a human body 25 $cm$ thick, and the film is pressed against the person’s back. Determine and discuss the range of magnifications that results. $m_1$ =    the magnification is  

  Sam purchases $+3.50-diopter$ eyeglasses which correct his faulty vision to put his near point at 25 $cm$. (Assume he wears the lenses 2.0 $cm$ from his eyes.)
(a) Calculate the focal length of Sam’s glasses.    cm
(b) Calculate Sam’s near point without glasses. his near point is    cm
(c) Pam, who has normal eyes with near point at 25 $cm$, puts on Sam’s glasses. Calculate Pam’s near point with Sam’s glasses on.    cm from her eyes

  As early morning passed toward midday, and the si +r-jwmfs52vxvj 70junlight got more intense, a photographer noted that, if she kept her shutter speed constant, she had to change thesi72j50 j-+vrmv fxjw $f$-number from $f/5.6$ to $f/22$. By what factor had the sunlight intensity increased during that time? $I_2$ =    $I_1$

Show that for objects very rkq9u*hk u1r.hhczxz+3c +h3 far away (assume infinity), the magnification of a camera lens is prhz ch. r u*+3cqu1+rh9x kkh3zoportional to its focal length.

  For a camera equipped wid ewv+ (uga9ynq+yp i;e,g /5 gz3x7sith a 50-$mm$-focal-length lens, what is the object distance if the image height equals the object height? How far is the object from the film?
$d_o$ =    mm
d =    mm

  A woman can see clearly with her right eye only when objects a3/ b qbclc1gr/re between 45 $cm$ and 155 $cm$ away. Prescription bifocals should have what powers so that she can see distant objects clearly (upper part) and be able to read a book 25 $cm$ away (lower part) with her right eye? Assume that the glasses will be 2.0 $cm$ from the eye.
$P_1$ =    D(upper part)
$P_2$ =    D(lower part)

  A child has a near point of 151 3l7ftnupj-k: pecuub+ 39iu $cm$. What is the maximum magnification the child can obtain using an 8.0-$cm$-focal-length magnifier? What magnification can a normal eye obtain with the same lens? Which person sees more detail?
$M_1$ =    $\times$
$M_2$ =    $\times$

  What is the magnifying power ofacw *7h/ m2hpvmv;f+ h a $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mountains tri(p3ve)rw9 ng0(e8ckvwmfk7q es to make a telescope using the lenses from his reading m8f73w 0c pnr 9(k()ew kegqvvglasses. They have powers of $+2.0-D$ and $+4.0-D$, respectively.
(a) What maximum magnification telescope is possible? $M$ =    $\times$
(b) Which lens should be used as the eyepiece?    D

  A 50-year-old man usj /bi tjdyjev+.cic1;99a8 jqes $+2.5-diopter$ lenses to read a newspaper 25 $cm$ away. Ten years later, he must hold the paper 35 $cm$ away to see clearly with the same lenses. What power lenses does he need now in order to hold the paper 25 $cm$ away? (Distances are measured from the lens.) $P_2$ = +    D

  Spy planes fly at extremely high ala,ewbjys:9 5 +g96y n,jx sznjtitudes (25 $km$) to avoid interception. Their cameras are reportedly able to discern features as small as 5 $cm$. What must be the minimum aperture of the camera lens to afford this resolution? (Use $\lambda=550\mathrm{~nm}.$)D =    cm

When shooting pictures at very short distances, exposure ti.k)q bsj3 p1p.xi:b8j yk:l tcmes must be increased because of the inc q :is.) j38b.jkbyxkpp1:ctl reased distance of the lens from the film for a focused image.
(a) Show that when the object is so close to the camera that the image height equals the object height, the exposure time must be four times longer (or 2 f-stops) than when the object is a long distance away (say, $$\infty), given the same illumination and f-stop.
(b) Show that if $d_o$ is at least four or five times the focal length f of the lens, the exposure time is increased by less than half an f-stop relative to the same object being a great distance away.

  The objective lens and the ar8d/( esej68c1fyxe eyepiece of a telescope are spaced 85 $cm$ apart. If the eyepiece is $+23$ diopters, what is the total magnification of the telescope? $M$ =    $\times$

  The Hubble Space Telescope, with an objective diameter of 2.4:2u ecru y6 )0asbnf5p m, is viewing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguish. Consiruc5s )y:u26a f0bn peder diffraction of light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lense )p,qtlaw3a(b- 6o dyds, one with $f=4.0\mathrm{~cm}$ and the other with $f=44\mathrm{~cm}$ are made into a telescope.
(a) What are the length and magnification? Which lens should be the eyepiece?
The distance between the two lenses is   cm
M =    $\times $
f =    cm
(b) Assume these lenses are now combined to make a microscope; if the magnification needs to be $25\times,$ how long would the microscope be?    cm

  An astronomical telescope has a magnification of 8.0. If the two lenses are 3 b1cqb1wb9ipl:m8did1ei x2 28 $cm$ apart, determine the focal length of each lens.
The focal length of the eyepiece lens is    cm
The focal length of the objective lens is    cm

  You want to design a spy satellkkt*s+0hi:2jd cy 7.q w97sz. bj vsenite to photograph license plate numbers. Assuming it is necessary to j+zchs k:7.w.t2ijs *0q9bn k y7dvseresolve points separated by 5 $cm$ with 550-$nm$ light, and that the satellite orbits at a height of 130 $km$, what minimum lens aperture (diameter) is required? D =    m

  A Lucite planoconvex ly6y sar kmr*p);v9 2wsens (Fig. Below) has one flat surface and the other has $R=18.4\mathrm{~cm}.$ This lens is used to view an object, located 66.0 $cm$ away from the lens, which is a mixture of red and yellow. The index of refraction of the glass is 1.5106 for red light and 1.5226 for yellow light. What are the locations of the red and yellow images formed by the lens? $d_{i\,red}$ =    cm
$d_{i\,orange}$ =    cm