Why is the depth of field greater, and the image sharper, when a camera lens iv6;2ov)sx3w( b2lskzg ;ai ebs “stoppki2 gw; v 2ba(os lv3e)z;6bsxed down” to a larger f-number? Ignore diffraction.

Describe how diffraction affects the statement that the depth of field is greateuvp*h.6j rmeav .1k 3mr and the image sharper when a camerapmr.*v hekjm.3 1a vu6 lens is “stopped down” to a larger f-number.

Why must a camera lens be moved farther from the film to focus on a closeroh: c dac2,qz6 objecthc:q oc6, a2dz?

Why are bifocals needed mainly by older persons and not generally by younger w ryz gy-(ib;7peo rizy 7(-yw;bgple?

  Will a nearsighted person who wears correcti 4,ewyky p,jg.ml3 rg85ap z9zve lenses in her glasses be able to see ge 3zy,j kr m9 ,pyl5azp8g4w.clearly 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 nearsightedddg8mpp 1 i5frt c ykf,9t3+u) or farsighted by looking at the width of the face through their glasses. If the person’s face appears narrower tk8u+ d5tfpp1ctrig d ,3fm9 y)hrough the glasses (Fig. Below), is the person farsighted or nearsighted?

In attempting to dis)k;v)a 5luj pycern distant details, people will sometimes squint. Why does thil;)5ju) vapyk s help?

Is the image formed on the retina of the human eye u0j l-6*w8s )a dixvtn)wawt r-pright or inverted? Discuss the implications of this for our per)swwj v* --lr )iatw6 8nt0adxception of objects.

The human eye is muc7x-ol3 jr vv6kh like a camera — yet, when a camera shutter is left open and the camera is moved, the image will be blurrjrx7 kv- l3o6ved; but when you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use cu1f/1xkj4puo onverging lenses. A simple magnifier is also a converging lens. j41/f1xupu okAre 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 usuallybqdpf8 h9 5frpv: p7p+ produce images that are colored at the edges. Why?rffp b:dh q8v7 95+ppp

Spherical aberration in a thin lens is mi,6gj 7ia )c p(lvyiv2inimized 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 shouldc a lji(y7p2),vg6i iv face the object? Use ray diagrams to show why.

Which aberrations present in a simple lenf:au+gu6g 2 yzs are not present (or are greatly reduced) in the human eyyaguf6:g+ u 2ze?

Explain why chromatic aberration occoaf7+0 9hqgw 0x9fniu 6no -gwurs for thin lenses but not for mirrors.

  By what factor can you6s7upwz:rlnuw7 f:z9jf(z5p improve resolution, other things being equal, if you use blue lil ( zpurf7jusz: n7w:z65w f9pght ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages for thez (c +d :fj :jcj;mmz/kpebv02 use of large reflecting mirrors in astronomical mk e:cczj z0j+p/f(vb2:j ;dm telescopes.

Which color of visible light would give the best resolution in a microscxb2 m:*hjdh* 7q.6tcr8hwxetope? Exp.qt x rehbdm w72xcj 8*6h*t:hlain.

  Atoms have diameters of , hm0ak8*/r8a4 tobd u7snf0k9xame q about $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stops rbdnh8 ggxoa7q6):1cv 4 l3dqcl 2 uw;zanging 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 abnj3t,p4n ck- 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 setting uz-x)h,dn rgiu;3zu iu5 +f0-j:nwr i 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 take df:/ kkt d:lno*f(o8bn 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 adjust4h /zrka fa5j.4 8s+f kc9uhbyed so that it is 200.0 mm to 206.0 mm from the film. For what range of object distances can it be adjustea59h kjsz4.bray fch8 4ku/+f d?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photograph a 28-mtall tree from a distance of;bepd 2x8i;wdxb am09 58 m. What focal-length lens should be used if 2b ;dw9;pdmxe08 xi bathe image is to fill the 24-mm height of the film?    mm

A “pinhole” camera u) ros. p*/g iuele2u/sses a tiny pinhole instead of a lens. Show, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particular, cons /si/eleuu2 so. pg)r*ider 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 exposure zv 2y kwnidl2 n-/lv.;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 2.0 r8vc(ynu 0*bk$cm$ 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 wu pl/o+vi.8i oore contact lenses corrected for the far / uo.l8+v piiopoint $(=\,\infty)$ 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 n g8 7yp+jjo3t 6/+-sspjwd ) wbmb:xaeear 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 po )o3-mv vx .,zhtxmc:sint 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’smuh (im; rdpsvdz)h 5;6e m;6y 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 b5rhcosl 60 v-ty 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 objects clearly only if they are betweef(gdg4 )ot8 )ekt0rgv 42kgee-qm 8mxf0 x2 cln 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 ino.jp wc8)k,,d4o oz w6shto0v Example 25–6 than the 2.0 $cm$ of a normal eye?    cm

  One lens of a nearsighted person’s eyeglasses has a focal length o x(xi t8 0nd(exf)(dzrf $-22.0 \, cm$ 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–lensp3m/n vweltj0pq: tau( g2. v2bu 17 n)s0inzs 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 and far poin l fiy)ca0z)qf l((0sdts 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 :pu)k; *:vs4pp; nu i*hyzt)(jzivvjof a lens used with a relaxed eye if its focal length is 12 p4i*)tjp*vzu)vy;sp:n(u; v z :j kih $cm$? =    $\times$

  What is the focal length of a magnifying glass ou.lmg)xcma 5l1cl1c4 f $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is ratedbc*s1hmjf o6 2 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 unscl/y wjmf0l q;e)-gf r,z,0sing 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*wsp: ozmm)d/,lgd-5ixhib + with 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 plac6 8f7zkuta5hl gf x2;z i-,ikted 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 of 8.pcs8n k/u cy3.3f nzh: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 ratxb pfsrqn6b 6e:(s/ 0muj(iw-ed 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 magnificatike+ dwe (auv6.on of an astronomical telescope whose objective lens has a focal length of 7.wd6+( euk vae6 $cm$ 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 j 4)e*vd-q n,npk1qdptelescope 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 lengfcg 1 ,uouw6lww 5:*)c)5v or4ni77dhukpykpth 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has its two lenses spaced ;lu7cm olzo2n)iag : 375.2 $cm$ 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 a rel r m(c6jhfvp0-axed 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 magnifyin:ma77dec 6 rczr ke i hvo/dgdr8,15+dg power of an astronomical telescope using a reflecting mirror wrodek d+i7g 5ae7hccrv6 /mz8dr:d ,1 hose radius of curvature is 6.0 $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appearsk c);3vwjjsn ydpo+i3v.;mj 2 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 its o p4u3rhuzp)u9zie vzx53+ h.f bjective mirror and a radius of cu3izz+zhu9pu px hu 3f).5v4re rvature 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 with a focal len*9z )odx.gsyuz y(t* ggth 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 1iwrqqo)*z33 s2.0$times$ 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 1t:g mbch-3avj n mlpk28 52b1q.8-$cm$-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 image is locate:)y ).u yx ah+sq8owz3 8jsered 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound microscope has a focal length of 2.70 dqy qrd+r:b0q 96fbn ,$cm$, 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, f.e4vk-o 3js0 cjz6tzplaced in contact, that have focal lengths3.0jct o j 6zzke-v4sf 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 amki g+ctwy -m:/9zi8 a wxj3w7 particular situation. A planoconvex lens of index of refraction 1.50 and radius of curvatu7zm w8jt+-9 wkg :i xamcwy3/ire $R=12.0\mathrm{~$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 (degm615kngu9g tc rees) set by diffraction for the 100-in. (254k9ggt1n6u cm5-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish t9 ofv tn n(e:/e;i5hu9yoo-p9ge ;kqko construct a telescope 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-mmi:jx*9dk.j ii dcn ffk(91qi0 camera 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 awgs8po(+ jdbz; 4txpi jgq g52/ay are barely 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 distinguish two car hc+l* k zx jru/8s8qiq)eadlights 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 areq( q ooxpry):7zqaj;* 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 n(fn wrun*zu u7pb2h8 (m fall on a crystal whose atoms, lying in planes, are spaced u(8nzp(2r uf7 wunh*b0.280 $nm$ 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 atz * 9,db6jebqm3 wfoigeq;:4p an unknown crystal. The second diffraction maximum is recorded when the X-rays are directed at an angle69zqg * ifejpbm4:e;wob dq3, of $\mathrm{23.4°}$ relative to the crystal surface. What is the spacing between crystal planes? d =    nm

  First-order Bragg diffraction is observed at 19wycig b0 3x 8gepbcw5t0i+ c$\mathrm{25.2°}$ 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 conventio2i s(kgb 3cc4h-u o6vfnal X-ray image that the X-ray beam consists of parallel rays. What would be the magnifi26 f3 gc4ih-cokbs( uvcation 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 ttnwzqn,tl w8 3;6 pbr9he sunlight got more intense, a photographer noted that, if she kept 3qnbt pl,rw tn;w8z69her shutter speed constant, 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 dz h08/bja, vl6xxb lcm 9vpjokg0,)) away (assume infinity), the magnification of a camera lel,)), jxgc0 v6vbamh/lp 8dj 9o0zbkxns is proportional to its focal length.

  For a camera equipped wita+c3jcej nubnt6 w- jt,saka655t.4bh 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 o/txabuyq :m t)(rv98b nly 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 poinxip:i8a/nf wj0a25 frt 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 poef zvb 43x7iytdbs01 ,ro5-0kaqv1 pf wer of a $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mountains tn7cutoem:po (y6; k;g ries to make a telescope using the lenses from his reading glasses. They have powers7(otom6 :kn; gu c;pey 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 use 7mzy6dnhji m,41 m5qes $+2.5-diopter$ 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 extr -i v;ocw.3)+fdqtjyv emely high 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 distancv u328z nwyydqfvu 8fs z q/*l*zh.j9(es, exposure times must be increased because of qw3vu/l*hn88zuv9 s qyz(fzdyjf * 2.the 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 th 2. 5vl0nz5ady.4xdiex 9rzjne 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 objeek3ksgi;a dz0sf;3*k ctive diameter of 2.4 m, is viewing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguish. Consider k03;sa;d3iesg kzk *f diffraction of light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lense-t r7axb62/+mo.mj qg sx-glss, 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/m,ysg amc9st m+,of * 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 satellevnkhy-)0 f;iite to photograph license plate numbers. Assuming it is necessary to resolve poify0 -;nhiv)kents 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 lens (Fig. Below) has on(u3ca1 l8j xkke 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