Question

iv. An object is 14 cm in front of a convex mirror. The image is 5.8 cm behind the mirror. What is the focal length of the mirror? A. 4.1cm B. 8.2 cm C. 9.9 cm D. 20 cm​

Answer 1

Answer:

C. 9.9 cm

Explanation:

The location of the object, u = 14 cm

The location of the image, v = 5.8 cm

The focal length of the mirror, f = Required

The mirror formula for a convex mirror is given as follows;

$\dfrac{1}{u} -\dfrac{1}{v} = -\dfrac{1}{f}$

Therefore, we get;

$\dfrac{1}{14 \ cm} -\dfrac{1}{5.8 \ cm} =- \dfrac{41}{406 \ cm} = -\dfrac{1}{f}$

Therefore;

$f = \dfrac{406 \ cm}{41} \approx 9.9 \ cm$

The focal length of the mirror, f ≈ 9.9 cm