Question

Hello try this!

help me!​

Answer 1

Explanation:

$helloo \\ \\ you \: can \: easily \: do \: this \: question \: \\ by \: lens \: makers \: formula = > \\ \frac{1}{f} = (mew - 1)( \frac{1}{r1} - \frac{1}{r2} ) \\ (where \: mew \: is \: refractive \: index) \\ \frac{1}{f} = 0.5( \frac{1}{20} - \frac{1}{ - 20} ) \\ \frac{1}{f} = \frac{1}{2} ( \frac{1}{10} ) \\ \frac{1}{f} = \frac{1}{20} \\ f = 20 \: cm \\ \\ \\ hope \: it \: helps \: uh..$

Answer 2

Explanation:

(Hi bro!

I'm answering this question again with new ID..)

$\huge\underline{\underline{\sf ANSWER}}$

Given that:

r1 = 20

r2 = -20

mew (refractive index) = 1.5

By using lens maker's formula...

$\frac{1}{f} = (mew - 1)( \frac{1}{r1} - \frac{1}{r2} ) \\ \frac{1}{f} = (1.5 - 1)(( \frac{1}{20 } - ( - \frac{1}{20} )) \\ \frac{1}{f} = (0.5)( \frac{2}{20} ) \\ \frac{1}{f} = \frac{1}{2} ( \frac{1}{10} ) \\ \frac{1}{f} = \frac{1}{20} \\ f = 20cm$

I hope solution is clear...