Question

A convex rear view mirror of a car is 3m. Find the location of the image of the bus that is 7m behind the car?

Answer 1

Answer:

The image is this formed at 1.2354 m behind the mirror.

Thus 1.2354 is the correct answer.

Explanation:

Given data:

A convex rear view mirror of a car = 3m.

To Find :

the location of the image of the bus that is 7m behind the car.

Solution:

R will be positive as the mirror is convex mirror.

Radius of curvature = + 3m

Object distance will be negative

u= -7m

We have to find image distance v=?

The focal length is given by the formula

f= R/2

=3/2

= 1.5m

The mirror formula is given by

1/f = 1/u+1/v

Hence 1/v = 1/f - 1/u

1/v = 1/1.5-1/(-7)

= 1/1.5+1/7

=0.6666+0.1428

=0.8094

Thus 1/v= 0.8094

Thus v= 1.2354m

Hence,

The image is this formed at 1.2354 m behind the mirror.