Author Question: A singer is farsighted and cannot see objects clearly that are closer than 80.0 cm from his unaided ... (Read 57 times)

azncindy619

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A singer is farsighted and cannot see objects clearly that are closer than 80.0 cm from his unaided eye. What is the refractive power of the contact lenses that will move his near point to a distance of 25.0 cm from his eye?
 
  A) 2.75 diopters
  B) -2.75 diopters
  C) -4.72 diopters
  D) 4.72 diopters
  E) 7.00 diopters

Question 2

A person's eye lens is 2.7 cm away from the retina. This lens has a near point of 25 cm and a far point at infinity.
 
  (a) What must the focal length of this lens be in order for an object placed at the near point of the eye to focus on the retina? (b) What must the focal length of this lens be in order for an object placed at the far point of the eye to focus on the retina?



brittanywood

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Answer to Question 1

A

Answer to Question 2

(a) 2.4 cm (b) 2.7 cm



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azncindy619

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Both answers were spot on, thank you once again




 

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