Why is the depth of field gre(o)i,:f(s*xxuqxt( l eyr-o*g) y)k8clhzp nater, and the image sharper, when a camera lens is “e* :( (yit-qkxu*xyonl os)f(lcr, gx )phz )8stopped down” to a larger f-number? Ignore diffraction.

Describe how diffraction affects the statement that the depth of fr rqfhx:oe/ dlb*rd378: t 7vdfj/)fg ield is greater and the image sharper when a camera lens r rjgxdf:vf7 o q/l8h:*d/ f bret)7d3is “stopped down” to a larger f-number.

Why must a camera lens be moved farther from the filmn;o v4zio /ij4 to focus on a closer objec;j 4n4ovozi/i t?

Why are bifocals needed mainly by older persons an.juce oy:4+s en(br)ed not generally by younger peopleb n cse(yre. ou:)4+je?

  Will a nearsighted person who pb:5ov x :y v40d0olpmwears corrective lenses in her glasses be able to see clearly underwater when wearing those gl4m:50 bvl pxop0v:d oyasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether a person is nearsighted or farsi-j.)ok;xl ti4tqmwz n2:q/e rghted by looking at the width of the face through their glasses. If the person’s face appez rit-k./:q w4j ;l)mxqeo2ntars narrower through the glasses (Fig. Below), is the person farsighted or nearsighted?

In attempting to discern distant details, peoplehgh99e ;5azu y(i) gte will sometimes squint. Why does this5heeiy ;ga hgz (9)9ut help?

Is the image formed on the retina of the human eye upright or inverted?y oqt28;e gzqs7*el*f zlr 0;c Discuss the implications of thegl; **;fq rtqz2l80zy7 eocsis for our perception of objects.

The human eye is much like a camera — yet, when a ncm koz2lfv8i ,e:+j- camera shutter is left open and the camera is moved, the image will be blurr,n2 fez: ov+k-8l micjed; but when you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use converging lenses.c3:vv+uxl w)q)v4 lla A simple magnifier is also a converging lens. Are reading glassesvux)34q+c v :lvw l)la 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 images that are cvw8*cc xfc1 lw o4)kfvgy3s.,olored at the edges. Why?y)w cfv ,4o.31cxklv8 g *scwf

Spherical aberration in a thin0.pu)f-bm/ oxqozx5w6cq xl i-,k2d p lens is minimized if rays are bent equally by the two surfaces. If a planoconvex lens is used to f )o-iwulz-.cq 2q, x0bm dxp/kp6x5oform a real image of an object at infinity, which surface should face the object? Use ray diagrams to show why.

Which aberrations present in a simple lens 5:vcqmb0s kbjcf)w4qp7 .gg7 are not present (or are greatly reduced) in the human ek v gfcs wp4:q)7cqm.bgjb750ye?

Explain why chromatic aberration occurs for thin lenses but not for mirro7 h5wr h,f8itqrs.

  By what factor can you improve resolutigs.e4j61 v ei:xbb1/ jl vrjrpo3b;o6 on, other things being equal, if you use lv 6vjso4.e eri:b ;3o11jg/b xpbr6jblue light ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages for 8pg03bp fff tg/n33s fnj .w*t)csd3lthe use of large reflecting mirrors in astronomical telescopes3fsbf tg* dfw/)j l0n33. ng t3sc8fpp.

Which color of visible light would give the best resolution in a microscope? Ex3bfzwka 8a(c*plain aw3c z(b8*fak.

  Atoms have diameters of ab 8ycjy2lu;vb:zm u6 e8x c);daout $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stops rangingaeu y5ka s, o2j*f-0cy 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 len68sqh v*/w9szyys ,gc s 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 ;puy ,k+;d dzbl m:a l(xz2;jna 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 is taken a qe ghfcjgi 46f:(i/0gt $f/16$ 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 adjust,nv)ge01, a -u jvn4bs d*skysed so that it is 200.0 mm to 206.0 mm from the film. For what range of object distances can j 0av-),s syn4kdvbs,1nueg *it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photoef-iea +x ac 1:5yo9dagraph a 28-mtall tree from a distance of 58 5 c+ad-:1 eoe9 fiayaxm. What focal-length lens should be used if the image is to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiny pinhole instead of a lens.l6 )jqk/zd g,x Show, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particular, consider two point object)d qxk,6j/lg zs 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 exposure ise:ve nk7)ks8b/z(j kuva7 q(e $\frac{1}{250}\,s$ 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 abo;w 6/* cginzynut 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 25–6 wore contact lenses ,5, xymk5 ttqa-gb0x gf *pt.icorrected for the far poinqt5,5-px , t b ktmay0.*xigfgt $(=\,\infty)$ 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 neede29hu hcsum /z4p1ix.z4 0 mccbd for a person whose near 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 pow3e/ykcjr7anw+m 5dkpr(;p , n+/lj fint 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 a9m -4 dr *ldjeljor5u 9)ej2oz book at arm’s length, a distance 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 rx;rw u 6ev9h;q:o tak4ah /2in/lgu3by 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 objewslkd 5-to g (lhv lf 7i+glv(2d(2t:pcts 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 eye in Examp8 v56d rexajl -z3wr,d9 knj;ble 25–6 than the 2.0 $cm$ of a normal eye?    cm

  One lens of a nearsigq1efgb rfm9 ;t(lv;c +7rv7ekhted person’s eyeglasses 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 length of the eye–lens system when viewing an objwv1-k2zw (rb4 hv ml;d1gkz+ject
(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 pointsb3 jl5w7x/t fkig nz:/ y:mze, 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 eye if its foca4pt:sx e12s eql length is esp1x :2et4q s12 $cm$? =    $\times$

  What is the focal length of a magnifying gl u/g *cutnnvso-6xri7y u9* q8ass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated ep-4g)mom wg 4uvh e8,at $2.5\times$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 9.00cej/j2d( g 0dl-$cm$-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 9.50nh+ hw: o*db9gy5 b2dh-$cm$-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 plkk.ka8 1eszo ;upd+h:k gl5 l8aced 5.55 $cm$ 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 o j3da. p2 o0bz.(rud ccjnf+c9f 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 j pt w6rw7qs .s;ycm 5z4;rk5frated 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 rndc t+r0m /*rho 8o1o-z.e orof an astronomical telescope whose objective lens has a fo /+*0ro8 eoco ro1hmrz.dr-ntcal 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 osp:jgjh3*4z cf an astronomical 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 fh3 .x4ntpfb) has an objective with focal length 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has itso,0d.a g7k+mgkeni ji:0 ly4 s two 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 forta t+22otuhu) 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 astronomical telescope usingsk3x*g qs nvip f5.x,* a reflecting mirror whose v3 *ix gsnk5 .s,fpq*xradius of curvature is 6.0 $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appears 5 +yoo-9e6ts1wvcm uetp0 1jcjyij,0 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. Below) has a radius of curvature of 3.0 m for ito0n1 bdqo d6l-s objective mirror and a radius of curvature ofql -1odbo0 d6n $-1.50m$ 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 len36 ,9c f3dmbb9b4o c )wvgxbipgth 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 12r7d lth/c i67e.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 1.8o:y bvip0 b,23n s9yix-$cm$-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 finalwfrq( +t;dbgr-q ++c l image is located 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound micrbqbc9n :mw3s8 oscope 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, riy z;scyhvohf wh*qr2p0rkh7.; 4 9 5placed in contact, that have focal lengh 2 ry50zpisr.r hk ohfc wh;y4qv*;97ths 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 sphericag2w,vix n2cz-m ;xs a t5fd9m3l aberration in a particular situation. A planoconvex lens of index of refraction 1.50 and radius of curvature 9vx2dg2wt in,xs m5m c-3fz;a$R=12.0\mathrm{~$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 resolu)1k*z *agdpamtion limit (degrees) set by diffraction for the 100-in. (25m*d )kaz1 *gap4-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to construct a telescope that can resolve featurespf 47l/f ;jn;a7u xzdl 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 camern-dyef yun-.xc x/0pay gj1)+a has 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 )sj,m krpfm.d 5 e7;sbbarely resolved by 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 dik(s rzib8 ;4omstinguish two car 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 are separated by abous3. gh45 y ueb27l lfkyduhg5,t $400\times10^6\mathrm{~m.}$ 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 --*jx5q.fnn ho9mvvu 0.133 nm fall on a crystal whose atoms, lying in planes, are spaced fq .5h9-- vmovnxun*j0.280 $nm$ 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. T.chl2uoha l*;tbm xs.vzo qk0: 9+qv1 he second diffraczshb :x;9 oc. tkq1vu2qlm0. oahl*v+tion maximum is recorded when the 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 diffraction isf q;fy*uvd5,c 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 X-ray beam consists of pe);6g )sd.f0m4hzfxqy+ nsiqg4 am (sarallel rays. What would be the magnification of the image? a the f4f 0s64s)esgxn.;qm h gqz m(y+d)i amagnification 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 pasmac+,m6 p6rs x.gm j:vv,,urog.9hxssed toward midday, and the sunlight got more intense, a photographer noted that, if she kept her shutter speed cr+ ,os h.xmu 6pm9j.c6 v,,mxsrg :avgonstant, she had to change 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 morw04/m:p osfe h 8q+oagnification of a camera lens is proportional to its focal lfhms re o:oo/0q+4wp 8ength.

  For a camera equipped j-o6 yzl p/d5ewith 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 arv27i g2opj)4ne5ye ppe 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 poeh m 9s kz/5vl-.(.h 0gaxhu*xogcdp2int of 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 ofe2yvf( 5l(q cv 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 telescope using the lenses tw2huf n/2,er from his reading glasses. They have powers of/rf2et,w n2uh $+2.0-D$ 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 uses l3 sh*+s.1o pkmsuxi4y5ww, g$+2.5-diopter$ 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 al; hiblqm :v, 0t/zkxi/titudes (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 increaseuy rk.1 t3 r56uvktb3 99e0vfcacra-v d because of th1 eu 5.9 r9-fyrub6 3crvtva3ackk0tve increased 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 eyepiece of a telescope avy:cgby z f:*dl p97e-re 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 diamet3;)fhyax gzj 4er of 2.4 m, is viewing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguish. Consider diffraction ohgx)yja; 4f3zf light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lenses, on: em/ vjj84 /jq2 nqaz 1g+nwxx;3edya7k2gdke 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 hasyswlzq9 qdz) su526( k a magnification of 8.0. If the 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 sp1yvap d/tjuyt. /tc q9q3)d/t y satellite to photograph license plate numbers. Assuming it is necessary to resolve points separated by 5 jpv/ t)qyd1cd t/uta9 y/.qt3$cm$ 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 lens (Fig. Below) ud.d6en-8v t rhas 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