Question

A 7.5 cm object is 14 cm from a concave lens, which has a focal length of –7 cm. What is the distance of the image from the lens? Round your answer to the nearest whole number. 5 cm –5 cm 14 cm –14 cm

Answer 1

Answer:

-5 cm

Explanation:

We can use the lens equation:

$\frac{1}{f}=\frac{1}{p}+\frac{1}{q}$

where

f = -7 cm is the focal lenght

p = 14 cm is the distance of the object from the lens

q is the distance of the image from the lens

Solving the equation for q, we find

$\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{-7 cm}-\frac{1}{14 cm}=-\frac{3}{14 cm}\\q=\frac{-14 cm}{3}=-4.67 cm \sim -5 cm$

Answer 2

Answer:

-5 cm

Explanation:

Just took it : )