Aperson can read the newspaper when it is held at 60 cm from his eyes. what should the focal length of his contact lenses be to allow him to read the newspaper comfortably at a distance of 30 cm? (a) -30 cm (b) 60 cm (c) -60 cm (d) 30 cm
Solved
Show answers
More tips
- P Photography and Videography Understanding HDR: How It Works and Why You Need It...
- G Goods and services Which TV is better - LCD or Plasma?...
- S Sport How to Learn to Pull Up on Monkey Bars?...
- L Leisure and Entertainment Scrapbooking: What is it and Why is it Becoming More Popular?...
- C Computers and Internet Where did torrents.ru move to?...
- B Business and Finance Understanding Cash Flow: What It Is and How It Works...
- C Computers and Internet What Are Peers and Seeds in Torrenting?...
- H Health and Medicine 10 Simple Techniques on How to Boost Your Mood...
- G Goods and services How to Choose the Right High Chair for Your Baby?...
- S Style and Beauty Learn how to tie a keffiyeh on your head like a pro...
Answers on questions: Physics
- P Physics Aman is parachuting when he accidentally drops his wallet. the man is falling at a rate of 2.2 m/s and the wallet hits the ground with a speed relative to the parachuter...
- P Physics Diana would like to observe the movements of a paramecium. which of the following tools would be best for diana to use? a. hand lens b. light microscope c. scanning...
- P Physics The half-life of a second-order reaction does depend on [a]0, unlike that of a first-order reaction. the quantity [a]0 remains the samethe half-life of a second-order...
- P Physics Julie throws a ball to her friend sarah. the ball leaves julie s hand a distance 1.5 meters above the ground with an initial speed of 16 m/s at an angle 28 degrees;...
- P Physics Dynamics newton s 1st & 2nd laws name weaver com across down 1 if you are standing on a bus and the drivor slams on the brake you will fall_ 3 unit for force...
- P Physics Now assume that Alice and Bob are twins, and Alice left Earth and Bob stayed behind fixing his spaceship. If Alice spent some time moving near the speed of light...
- P Physics If, instead of being frictionless, the slope instead applied a friction force of 80 N to the sled, how much would the spring compress...
- P Physics A 10 kg mass car initially at rest on a horizontal track is pushed by a horizontal force of 10 N magnitude. If we neglect the friction force between the car and...
- P Physics A dust particle on a phonograph record rotates at a speed of 45 revolutions per minute if the particle is 10 cm from the axis of rotation. Find. 1) its linear speed...
- P Physics A classroom measures 3 m X 4m x 6 m. Calculate the volume of air in the room. Give your answer in a cubic metres (mº)....
Ответ:
Option B IS CORRECT.
Explanation:
The person suffers from long sighted-ness. The near point has gone far . For
an object kept at 30 cm to be visible, the image of it must be formed at 60 cm ie the ray of light must appear to be coming from 60 cm . for it convex lens is required. So
u = -30 cm
v = -60 cm
Using lens formula
1/v - 1/u = 1/f
- 1/ 60 + 1/ 30 = 1/f
( - 1 + 2) / 60 = 1 / f
f = 60 cm
Option B IS CORRECT.
Ответ:
Applying the same formula in the secound situation: