Question

An object is 14 cm in front of convex mirror, the image is 5.8 cm behind the mirror. What is the focal length of the mirror

Answer 1

Answer:

4.10cm

Explanation:

p=-14cm

q=-5.8cm

f=?

1/f=1/p+1/q

1/f=1/5.8+1/14

1/f=14+5.8/14*5.8

1/f=19.8/81.2

f=4.10cm

So,

4.10cm is the answer

Answer 2

Given,

Object distance from thr4 mirror=14cm

Image distance=5.8cm

To Find,

The focal length of the mirror.

Solution,

Object is at in font of the mirror means ,

u=-14cm

Its image is behind the mirror means,

v=-5.8cm

We have the formula that,

1/f=1/v+1/u

1/f=1/5.8+1/14

1/f=(14+5.8)/(14×5.8)

1/f=19.8/81.2

f=4.10cm

Hence, the focal length of the mirror is 4.10cm