- #1

generalslip

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## Homework Statement

Got some work from my dad, but one question kinda stumped me.

A short sighted person can view an object clearly only when it is between 11 cm and 19 cm from her eyes. Calculate:

1. The Focal Length of the specatacles required to give her a near point of 25 cm.

## Homework Equations

I don't know what equation to use here. I usually see questions about image and object distances and object distances using the 1/u+ 1/v= 1/f equation, I've never seen one like this.

## The Attempt at a Solution

I just assumed, 1/.25 + 1/infinity = 1/f

1/.25 + 0 = 1/f

1/.25 = 1/f

4 = 1/f

f = 1/4

f= .25