{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

PHY122_L20PostingAfterLecture

PHY122_L20PostingAfterLecture - PHY122 Physics for the Life...

This preview shows pages 1–9. Sign up to view the full content.

PHY122 – Physics for the Life Sciences II Lecture 20 The Eye and Optical Instruments HW 12 due Sunday, 20 Nov. at 8 pm Note: Clicker Channel 21 11/15/2011 Lecture 20 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Lecture 20 2 Converging Lens, Ex. 2: object inside f an object is placed at s= 10 cm < f = 15 cm . Calculate and construct the image as before: 3 construction lines: parallel to axis, through O , through focus – Calculation: Note: for s < f : virtual upright image; 1 < m < 1 1 1 ' s f s = - object h s s h image O f f 11/15/2011 1 1 1 15 10 30 = - = - ' 30 cm s = - ( image!) virtual ' s m s = - 30 3.0 10 - = - = + ( image!) upright 1 1 1 ' ; ' s m s s f s + = = - (Too little time in Lecture 19 to present but posted online. Review briefly now.)
Lecture 20 3 Diverging Lens, Ex. 1 A concave-concave lens has radii of curvature R 1 =12 , R 2 =24 cm and index of refraction n= 1.5 . Calculate the image of an object placed at s = 24 cm from the lens by i ) geometrical construction, ii ) calculation… – Construction: focal point: 3 construction lines: parallel to axis, through O , through focus – Calculation: Note: for s > 0 : virtual upright image; 0 < m < 1 1 1 1 ' s f s = - sign convention: R> 0 if the center of curvature is on the OUTGOING side of the interface!! h h object s image s O f f All divergent rays! 11/15/2011 ( ) 1 2 1 1 1 1 n f R R = - - 1 1 0.5 12 24 = - - + 0.5 8 = - 16 cm f = - ( image!) virtual ' s m s = - 9.6 24 - = - 0.40 = + ( image!) upright 5 48 = - ' 9.6 cm s = - 1 1 16 24 = - - (Too little time in Lecture 19 to present but posted online. Review briefly now.)

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Lecture 20 4 Summary Mirrors/Lenses Summary: R > 0 for center-of-curvature on outgoing side; s and s’ > 0 for real image; if not, virtual image { 1 2 mirror glass lens in air 1 1 1 1 1 2 ( 1) ' ' n s s f R R R s f m s f s + = = - - = = - = - 1442443 lens/mirror type s > 0 ( REAL object) s’ m= –s’/s =f /( f – s ) image type converging/ concave ( f > 0) 0 < f < s s’ > 0 < m < 0 real, inverted 0 < s < f s’ < –s 1 < m < virtual, upright diverging/ convex ( f < 0) s > 0 f < s’ < 0 0 < m < 1 virtual, upright flat ( f = ) s > 0 s’ = –s m = 1 virtual, upright 11/15/2011 (Too little time in Lecture 19 to present but posted online. Review briefly now.)
In this figure the image is produced by a lens. Where is the lens? 11/15/2011 Lecture 20 5 1 2 3 4 5 2% 9% 2% 75% 12% 1. at A 2. at B 3. at C 4. at D 5. at E correct

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
11/15/2011 Lecture 20 6
The lenses that are shown here, are they di di diverging or con con con converging? 11/15/2011 Lecture 20 7 A. B. C. D. E. F. 2% 4% 4% 13% 56% 20% A. all are converging B. A and B are converging, C is diverging C. B and C are converging, A is diverging D. C is converging, A and B are diverging E. B is converging, A and C are diverging F. all are diverging A B C 1 1 1 ' s s f = + correct

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Lecture 20 8 The Eye The eye is a variable-focus, color-imaging, detection system with a built-in diaphragm ... the normal healthy eye can provide a sharp color image on the retina for object distan- ces between ~ 25 cm (the near point ” with tensioned ciliary muscle; actual value varies with age) and infinity (the far point with a fully relaxed ciliary muscle).
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 35

PHY122_L20PostingAfterLecture - PHY122 Physics for the Life...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online