Answer:
122.4 cm
Explanation:
[tex]d_{p}[/tex] = distance of phone from eye = 44 cm
[tex]d_{e}[/tex] = distance of eyeglasses from eye = 2.0 cm
[tex]d_{o}[/tex] = Object distance = [tex]d_{p}[/tex] - [tex]d_{e}[/tex] = 44 - 2 = 42 cm
P = Power of the eyeglasses = 1.55 diopter
focal length of eyeglass is given as
[tex]f = \frac{1}{P}[/tex]
[tex]f = \frac{100}{1.55}[/tex]
f = 64.5 cm
[tex]d_{i}[/tex] = image distance
using the lens equation
[tex]\frac{1}{d_{o}} + \frac{1}{d_{i}} = \frac{1}{f}[/tex]
[tex]\frac{1}{42} + \frac{1}{d_{i}} = \frac{1}{64.5}[/tex]
[tex]d_{i}[/tex] = - 120.4 cm
[tex]d_{n}[/tex] = distance of near-point
distance of near-point is given as
[tex]d_{n}[/tex] = |[tex]d_{i}[/tex]| + [tex]d_{e}[/tex]
[tex]d_{n}[/tex] = 120.4 + 2
[tex]d_{n}[/tex] = 122.4 cm
