Question

a convex mirror used as a rear view mirror in a bus has a focal length of 200 cm if a scooter is located 400 cm from the mirror find the distance of the image​

Answer 1

Answer:

Explanation:

ANSWER:-

We know that:-

$\sf{\dfrac{1}{f} = \dfrac{1}{v}+\dfrac{1}{u}}$

• f is focal length
• v is distance of image
• u is distance of object

Concept:-

To apply the mirror formula

Lets Solve!

• Here, v is to be found.
• Focal length is positive 200 cm
• Distance of object is negative (real) 400 cm

$\sf{\dfrac{1}{+200} = \dfrac{1}{v} - \dfrac{1}{-400}}$

$\sf{\dfrac{1}{v} = \dfrac{1}{200}-\dfrac{1}{400}}$

$\sf{\dfrac{1}{v} = \dfrac{400-200}{200 \times 400}}$

$\sf{v = 400 \ cm}$ is the required answer.

Answer 2

Explanation:

Focal length (f) = +200 cm

object distance (u) = - 400 cm

Now ,

1 / f = 1 / v - 1 / u

1 / + 200 = 1 / v - 1 /- 400

1 / v = 1 / 200 - 1 / 400

1 / v = 1 / 400

Then ,

v = 400 cm

The image is formed 400 cm behind the mirror. The nature of image is virtual because a convex mirror always forms a virtual images.

Hence

The magnification in this case :-

Image distance /object distance = 400/- 400

= - 1

Magnification (m) = - 1

Thank you