Why is the depth of field greater, and the image sharper, when aqy o0vw/vkzi/s ;y 3e8 camera lens is “stopped down” to a larger f-numberwse;/ivyq/ o3zy k8 v0? Ignore diffraction.

Describe how diffraction affects the statement that the depth of field is grearp4lbi*nmz06-xhn3 ster and the image sharper when a cameraz hr6n4p0xb3- sln* mi lens is “stopped down” to a larger f-number.

Why must a camera lens be moved farther from jx+m+5.yp ye3p /bzp y/b6bjtr ij67bthe film to focus on a closer object?7+ bmibp6 y/z/6 yx5 p+rjjbytpej3b .

Why are bifocals needed m 4ae,abs+ vk6hainly by older persons and not generally by younger people?6hk+a4a sbv,e

  Will a nearsighted person who wears corrective lenses in her guq;:l 3 q3kpkplasses be able to see 3pq: pul;q3 kkclearly underwater when wearing those glasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether a person is nearsighted or farsighted by looking d4 dhfh:o5 vn 8vt:;rmat the width of the face through their glasses. If the person’s face appears narrower through the glasses (Fig. Below), is the person farsighted or hdfh8n :o;:v 54dv tmrnearsighted?

In attempting to discern distant details, people will some(f 5m+fj;npl0 lij4mztimes squint. Why does this ;4zl ( njfmf 0l+j5imphelp?

Is the image formed on the retina of the human eye upright or inv6 u:85 uvtxcweerted? Discuss the implications of this for our perceptiu58ecx:w 6utvon of objects.

The human eye is much like a camera — yet, when a cixv d12t1zh4i amera shutter is left open and the camera is moved, the image will be blurred; but when you move your head with yo1ih2id1x4t zvur eyes open, you still see clearly. Explain.

  Reading glasses use converging lenses. A sr0c94u i0o 8kf(6*fb gjt: wy saj:iebimple magnifier is also a converging lensufr0 48b9ijsyagew* 0itbk jf:oc6:( . Are reading glasses 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 produce image;d)2pn qtuby 4s that are colored at n 4ybt2pu)dq ;the edges. Why?

Spherical aberration in a thin ,xow iev2:jw1y2pmj9 lens is minimized 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? p:jjw 9x1 vei,o2w2my Use ray diagrams to show why.

Which aberrations present in a simple len sy52 gto6juaqqh4 qawl8.5t8 s are not present (or are greatly reduced) in the 6 5 sq88a.y4aqgw5u ljt2qoth human eye?

Explain why chromatic aberration occurs for thin lenses but not fory3g f2o8 z-;wqao1fcz mirrors.

  By what factor can you improv x )wt4th(8o q.mhp5hqe resolution, other things being equal, if you use blue li8oh4) ttmh(qhq.xwp5 ght ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages f4*ub3)mavi a lor the use of large reflecting mirrors in astronomical telescopalam) 4 b3vui*es.

Which color of visible light would give the besmv;rqg,8s7ab4mta 8i rkw-51 rw8zl,uj u: pst resolution in a microscope? Expltrmp i,rulvw854jk-:q azsgau8m1b7;8 ,srw ain.

  Atoms have diameters of abof /hz+q(dhz5 zut $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stoa,zd6 h qvifu m8w56 c4u1ca2zps ranging 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 lens has,4 pk9anq,lsp +tmbxkt 9 dr*(8q sp9d a 14-$cm$ focal length and a lens diameter of 6.0 $cm$. What is its $f$-number? $f$/  

  A light meter reports that rdz16;xax )8o eb ado6a camera setting 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 i3v1e ,:q kwhpis taken 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 m15tr s, um,hnam to 206.0 mm from thu5r,a1mhn ts, e film. For what range of object distances can it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photograph a 28-mtall tree fri9f1-sde401sgcse/x 4ru0 alj ekwv*om a distance of 58 m. What focal-length lens should be used if the image is jvasf eg14 * 04du9-c/rx eswk1ei0ls to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiyfbd h*f r3;qu 9(8; fu5ktabrny pinhole instead of a lens. Show, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particular, consider two point oh;d* r8 3f ;quk b5uffa(r9bytbjects 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 e4vz73nqnln(.fzp o/s)3q3 aoudt ff2xposure 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 abou+x9 )pmi sa .u5ffs7spt 2.0 $cm$ 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 25vb *(ty+++pkgq z ydk6–6 wore contact lenses corrected for the fdbpv*t+g z+( 6kk+y yqar 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 near poinh ogga)e y *s31-qoj26zs.av ct 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 ccs91r8 o +*sz.l4bjbwtxnz 9 of 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 (o54mul4 xaisdistance 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 sfq7 (7ibha ,zis corrected by a $-3.50-diopter$ 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 objectsq bwzkrjjq04 m k3c)b//q1nn3 clearly only if they are between 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 eyy1s8q/0 l x7btn6q1qti;m b*g3ns e fgqlq09ge in Example 25–6 than the 2.0 $cm$ of a normal eye?    cm

  One lens of a nearsighted person’s eyeglasses has a fz+bbj: h+l8 vtf6v.nuocal 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 length of the eye–lens system when viewinga( (ztn*l pf) xopk6h3 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 and far point7g fmxi5l t7+qw.uw p-s 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 lenxwm l kglmwpleg)t-k.it xq:0w60q *:ks.d;8 s used with a relaxed eye if its focal length iw 0e*.w 0 l xpgmwkt-li6xkk.lsg mq8)dqt;: :s 12 $cm$? =    $\times$

  What is the focal length of a magnifyijea* qe)i;- dwng glass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated at ,)i0equx m r, mux*i3b$2.5\times$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 a 9.0 dfll (ye0:4:sphmm t0gz+7p x0-$cm$-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 wi8t x. h8v:-,u+ykuum0v f:z elz g9+b.qgp hdsth a 9.50-$cm$-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 e.:-. t/v kmpylpfv0i5.55 $cm$ 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 fn s3gwuic)1-krb:1n length of 8.5 $cm$ 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 ratez4 gzr /4v0kkqd 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 astronomicalr qt0 n.cfu38b telescope whose objective lens has a focal lengtt38qc0rnf bu.h 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 astronomical telescope is desirednq 6e 4yz,8g7mr h/ooh 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 f;lh3 o*js:ek length 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has its twu:ln+zrs:euo(.: a7frjbf/ki6g tkb;a ;m0 o o 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 adjustlbovh99x,8j(1wqhj , dp m2hmed for a 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 power of an astronoja86u3u5+zwxwr t (: ur ltp0ymical telescope using a reflecting mirror w:u x ljawz 3ywp06rr+ ttu8u5(hose radius of curvature is 6.0 $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appearsen2j hc/qb /i bdt+q7+ to be magnified 120$\times$ 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. m-;g7yrm3/ qh1mg0 koq hn1tzBelow) has a radius of curvature of 3.0 m for its objective mirror and a radius of curvature h z17-1m3mtqhr/ gnmqg;0 yokof $-1.50m$ 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 with a focal leny -v7)d)iq2ub-y lm, mav0m jrgth 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 1jy9n5-k.* s h ivbuk3o2.0$times$ 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.yjdoy2 ) -i54 jc,+ )q/mfh o-pnbvi3ovmcgi-$cm$-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 assuming that the final image3 :e.x rlcwwukv8 hx.l ;/dq9a is located 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound microscopeulx31o qz-gds9s *h+p-d i ni1 has a focal 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 is made of two very thin lenses, placed in contact, that h lljux, 6tg+bg:7x1bpv y(dg )ave foca,bxd1gt7 g6 lv jx+gp uly(:b)l 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 pa sm74 2wfbxdc 1rkd2 0ik6m(wh5pq ag)rticular situation. A planoconvex lens of index of refraction 1.50 and radius of curvatui)w 21q7awb k x0r4mkdcgs5hp m(6 2fdre $R=12.0\mathrm{~$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 resolution limit (degrees)jj4ax0.t *au) h3 1qmh7o ivyo set by diffraction for the 100-in. a*.xj0ym3o houai )14h 7q jvt(254-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to construct a telescope that can resolve features 7.0 z)paq88kt q (jstg+u6 $km$ 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 has a focal urwr 3q-z:b/zlength 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 xo.;6p77nu5 vjipuiosg * ef3a 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 phb2y5wq1 y yc7l p8r-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 arnhlf;p*4u; -sjrbn n0 e 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 cr h) wceq8mbn1: 2 (l)t/bdbmdyystal whose atoms, lying in planes, are spaced2mn m q1bd(l 8wb /td)c)yh:be 0.280 $nm$ 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 directed at an unknown crystal. The sestwz/ns2ks1 2cond diffraction maximum is recorded when tznts/k 2w1s2 she X-rays are directed at an angle of $\mathrm{23.4°}$ relative to the crystal surface. What is the spacing between crystal planes? d =    nm

  First-order Bragg diffract 1lpeu gpu-l*9ion is observed 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 b 6g7 w,k8ezyaX-ray beam consists of parallel rays. What would be the magniey 6gk8,a wb7zfication of the image? a the magnification 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 jv9v 9 ,jl+if9,evlfnswq 1 +:s ytp*wsunlight got more intense, a photographer noted that, if she kept her shutter speed constant, she had to changj+ lvsilj wws * ,:+vqp9yf,nev91tf9e the $f$-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 far away (assume infinity), the m i (0-o qsf3j3m5xeh(w/ pawnv.zys2lagnification of a ca3iwa.pnvw (xz/5lsse(hqfo032m -yj mera lens is proportional to its focal length.

  For a camera equipped with (;i1+ soyl .za bzj-wwa 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 ondvm5w jtsc1; a2)og3 aly when objects are 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 ,*,ek ;as k - cyjmkq2ymje(/iof 15 $cm$. 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 of vy,hgw*)3 slt j3r+b 9gmdo,nf wdb; (a $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mountains tries to make a telescopes8wol3j 1l ;zr using the lenses from his reading glasses. They have powew;zl 8so j3l1rrs 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 uselmho4e3m f/g 5s $+2.5-diopter$ 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 higivrlt1 yr za(.74gt 6rh altitudes (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 times must be increa,9m8m6.yeb s8 glocxta1s7 pbsed because of the increased distance of the lens fm.7gmsceoby8t8 x 9p 1lba,s6 rom 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 eyepiece of a telescope are spaced 85 l e hq1rqu435u$cm$ 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 m, is viec;ntk84inzv8d7v e x0wing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguish. Consider dif 4dt8n;vzvkx 07 ni8ecfraction of light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lenses, one w l 4 +st9)5y+ujuobs-g is+qwrith $f=4.0\mathrm{~cm}$ 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 9 tt9;5zh kfnhthe two lenses are 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 gvxz-h0 wnt; f,i/r t,satellite to photograph license plate numbers. Assuming it is necessary to r i-fvt,g/h;z0w xnr,tesolve 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 cwr.7az(j;lw lens (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