Why is the depth of field greater, and the image sharper, when a8wxb(-jnjsk/rue 7e96yoo 6xc*y t io6t g2 1v camera lens is “stopped dooku 8 i/*o1n7 t6yve 6 bojgr(cte sx9yw6-jx2wn” to a larger f-number? Ignore diffraction.

Describe how diffraction affects t8zhjxmaq o( q .z5*i8;( xw5de nqhkc8he statement that the depth of field is greater and the image sharper when a camera lens is “ *zwid5nokhq ;j5a xxz.(8q8 meq8ch(stopped down” to a larger f-number.

Why must a camera lens be moved farther from the sl3+7 q 6o9yl rp ffu/f/2toccfilm to focus on a closer object? c/q7u /sfo2r69l3tfoy+l pcf

Why are bifocals needed mainly by older persons and not gene/rw/zz f8/qj brally by younger peoplez f w8qzj///br?

  Will a nearsighted person who wear7(zh el)wpv6x(n bv1ns corrective lenses in her glasses be able to (7( vn phl61e vn)bwxzsee 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 nearsighted or fa;mpgl4hb y;:srsighted by looking at the widtlmb :4syhp; g;h of the face through their glasses. If the person’s face appears narrower through the glasses (Fig. Below), is the person farsighted or nearsighted?

In attempting to discern ka; z(erv oe)c9pn ,q;distant details, people will sometimes squint. Why does this k,c parq;ne;ze v 9o()help?

Is the image formed on the retina of the human eye upright or inverted? Discussn brwf2l/f2z89tl2 s,a6d9. da roqtb the implications of this for92 szf2 ,arb/68 n ad9lfol2t.wqbtdr our perception of objects.

The human eye is much like a camera — yet, when a camera shutter is lnn9r ,ggp w*7fl16zd left open and the camera is moved, the1lf*n w,g d6gprn9l7z image will be blurred; but when you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use converging lenses. A simple magnifier is also a con9 7 2b34dits9*o-wlpd tqnii0rh hp7wverging lens. Are reading glasses therefore magnidwtb97d279p4t*o hp hili ws0- n qr3ifiers? ----待选择----yesno  Discuss the similarities and differences between converging lenses as used for these two different purposes.

Inexpensive microscopes for( ,: u6qg mu/z1ab:6r+zme ukuo h4k1w7qtkor children’s use usually produce images that are colored at the edges1kuq4mouk: 6,6w(k m 1zzrbuqg /aou:7+htre. Why?

Spherical aberration in a thin lens is minimized if rays are bent jps6 .v 91wzxu0nlu :lequally 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 6j0ll:sw vu .nu9pzx1ray diagrams to show why.

Which aberrations present in a simple lens are not present (or are grezuk2( 7:y+a ktaq 5jizatly reduced) intzz2kky: u ia +a(j57q the human eye?

Explain why chromatic aberration occurs f (g9;aop2o 3mql6;lvub9edz for thin lenses but not for mirrors.

  By what factor can you improve repnb i.mk*71du solution, other things being equal, if you use blue light (din 7 1*kbu.pm$\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages for the use qt.dvey:5p 4;p u xq.hof large reflecting mirrors in astronomical telescp; :tx vhy.qd4q5. peuopes.

Which color of visible light would give the best resolution i/6 do*bruld8tn a microscope? Expl dd r8l*tbuo6/ain.

  Atoms have diameters of about vr5-n vv8v 3km$10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has )mwy (nvpyb7wp *m)i5 f-stops 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 lene whcvrmad*oq1rm- 8b+w(3n3s 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 caoioq.n1oqjr 74/u o 3hc qkl4a24 hg7tmera 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 take+o we5y )tm r1hkzzquq-0z1: 8 bn6vnqn 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-lengtj1ce,-zgn b6lz/, vw ih lens can be adjusted so that it is 200.0 mm to 206.0 mm from the film. For what range of object distances ca, -ge6, 1cwiz/bvl nzjn it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photograph a 28-mtallygxtx.,.x fw(c8 2ka o;j k6vr tree from a distance of 58 m. What focal-length lens sh.rxjk gvy .f8 xc(, kaxw2;ot6ould be used if the image is to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiny pinhole inst ci9l 2 ,syif,,n;mxwsw8k)h aead of a lens. Show, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particular, consider two point ns ;9mfh,c82)iy xs, aiwkl,wobjects 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 exp (mzznvmzr. 1cw(nc9ru ws31 /osure 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.i- ncib map. 3ijkw/-x70h+kl 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 corrected3qcvrfk0)6uu qs; g;t4ihx /f for the far point q/ 0uq;u3x )tfs;k6g ifrhc4v$(=\,\infty)$ 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 neet-mnl*m1q odps,jj/* ded 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 p8x2nmj m aox+6e))ru(r vb.gw oint 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 distance of 4la/fe 4/r-z y; 9jdaq gqq9dl:bq4v.v5 $cm$ 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 a 9t5p(x atoyl xl q0m3qxn 4d-,5 l9ckz$-3.50-diopter$ 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 ,o/ nftzg.s u2between 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 nearsivzfbe7ix)p qf9eyjq7kha55 .4 36rkoghted eye in 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 ofcjs9np7orw0(ig q7 m yg+4 3gf $-22.0 \, cm$ 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/ncj 0)f48etjmg qkh4 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 points)y(mlqawyp8b 3 mhjo2-)t4 gv 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 magnificatdtw.xf9x7z x )ion of a lens used with a relaxed eye if its focal length is xd)xtxz 79.fw12 $cm$? =    $\times$

  What is the focal length of a magnifying glas 1a*6r 6 7riulqmz2wpfs of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated85ierx5;(g na p .eg9lupa+nu;cq c *c 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 9.0flprj vaz2- 100-$cm$-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 vj()q;k2rw tu0bdgfj) )p q.gdiewed 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 placel424i k lleb4)c-hjdhm 1ky 0sd 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 82h;gbh noh9g.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 ratpod w /8h9fo,hc7rcm sd,- 5ci )zjgo9ed 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 telescope whose objective lens hatja2cy ,t5thanmc4-+s a focal lengac4c- +2na t,th5tjymth 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 lhcits os19 5g0v+8usof 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 has an objective with focal-q)ak7v pu ),-nf jajj length 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has its two lenses spa* c+paiqy( mv7f ;;qabced 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 a m7pt cx0- m lsmi4s57n1my;jqdjusted 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 astronomi)*. c8x1c *s avra1xyw vaoke.cal telescope using a reflecting mirror whose cxwx8a.vka o*a.rs 1yv ) ec1*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 magg6tmif -:9ns lnified 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) hassuc2ki, kckb;k7-3 4 5bagjtd a radius of curvature of 3.0 m for its objecti-7c ,342 kkjukbiaksc5g d b;tve mirror 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 9;:uw/: g aftkoywbr n9ui //rwith 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 1bx-6orqn 8u 7zpj*4r o/u-xuv cmin:,2.0$times$ 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.f15qhqx8 ifxm2(0x2 c-bbfep8-$cm$-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 locizs.k*8kpvh)b/dkkc z k +)y, ated 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound m8d1o*i7xdn q oicroscope 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 h31dz7 btx+: i)hkromv ave focalz:o1b3d irk7hxvt+m ) 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 planoconvex lensp /hsu9 iw*:rt of index of refraction 1.50 and radiusws:*p u/r9hi t 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 resolution limit (degrees) set by diffrm.*pe67nuh y ;xk z uh6*o:4hae2 occcaction for the 100-in. (2x*hpouhezc7o 6. um*:n e6 hkc 2a;c4y54-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to constructbc):3/ rx nbz3a*zga a 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-mm camera has a+,m- 2fcov m3tbdc sj5 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 o/luu wm. oxu;5)an.oby 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 huhko 1s2)ob(p k*1h uljman eye distinguish 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 tro,+m+ -yih6v m zr6dseparated 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 0.1334 ofwmqt-4nhfmd(5mg4vc5 q - nm fall on a crystal whose atoms, lying in planes, are spacednm(m qhv4 fm5tof4d4-w gqc 5- 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 cryst+p3vegf*mqg)ztd+ v0 al. The second diffrad eg)z+ 3+0ptgvvq* fmction 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 diffraq1gbthgm/0+z)auq 6w ction 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 thej1n t0h,ilf) 8,w ybdv X-ray beam consists of parallel rays. What would be the magnification of the image? a the magnih,vjb n,l 0dyt w8)if1fication 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 sunlight7p:9inu+b mw y got more intense, a photographer noted that, if she kept her shutter speed constant, she had to change pin wym +b97u: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 (asp/mxv +kdq ,wn4 is;a/sume infinity), the magnification of a camera lens is proportional/n vpqsx,i+ ma/wk4 ;d to its focal length.

  For a camera equipped withjk jd lrz/0pwr4x2c+6 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 hes2ylq r47p0w 3e5yv:b pv h*srr right eye only 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 of ;f+ ncv 7)zp *c *fjmnl(s6jwx15 $cm$. 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 magnifyin/ g/3jvvgsz(ges :;w xljdfd,, dmff 5sdu 285g power of 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 le))g4wmsfgy0 qrw5a 9onses from his reading ga5ms) fw9qogwyr) 04 glasses. 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 use(wq;,2 oga s) elrv1ips $+2.5-diopter$ 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 ikv5:7g/a0 fi9 tsdptpwp1* uemely 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 distances, exposure t1:b.i hvyy 0dtimes must be increased because of the increased distance of th ytd.:h0 yvbi1e 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 telescofjc hwj17ubvfnbl03q1t9 wk;w/ e (0u pe 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 zkw r;5q,k;+r9c bcsnof 2.4 m, is viewing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguishrns, cc9r;5 bqk;w+kz. Consider diffraction of light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lense.z: -eqc ;i5y douuyr5s, 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 :bm.-xsg9g ,vvjd l xi,-up0whzva/* 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 spy satellite to photograph lied1d .0bw7w qrg0.qi4c bs+s*irn cs 9cense plate numbers. Assuming it sni..g d+w4b0qc br70di * eq91ssrwcis necessary to resolve 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 lens (Fig. Below) hy uj0se.r fkz02u+4msas 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