A certain person\'s eye measures 25.5 mm from the pupil to retina. (a) If we tre

Question

A certain person's eye measures 25.5 mm from the pupil to retina. (a) If we treat the eye's lens as a thin lens, what is its focal length when the person focuses on a pencil 30.0 cm from the eye? cm (b) While the person focuses on the pencil, what is the image distance for a wall 435 cm from the eye? cm (c) When a person focuses on something near them, an object that is farther away appears blurry because the background object's image... forms in front of the retina? forms behind the retina? is a virtual one ?

Explanation / Answer

Part A)

Apply 1/f = 1/p + 1/q

1/f = 1/30 + 1/2.55

f = 2.35 cm

Part B)

1/f = 1/p + 1/q

1/2.35 = 1/435 + 1/q

q = 2.36 cm

Part C)

From the answer to part B, you can see that the image is forming at 2.36 cm for the farther away object which is less than the 2.55 cm for the pencil. This shows that the further object is fuzzy becuase the image is forming in front of the retina.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.