Question

4.The image formed by a convex mirror of focal length 0.3 m is a quarter of the object . What is the distance of the object from the mirror?

Answer 1

Answer:

-90cm is the distance of the object from the convex mirror

Explanation:

As it is given that length of the focal length is 0.3m

After converting it into cm we have 30 cm

Focal length is positive so f is 30 cm

1/f=1/v+1/u

It is given that the image is quarter of the object so magnification is the quarter.

So, m=1/4

now the formula is m= -v/u

so, 1/4 = -v/u

we have u = - 4v

Now putting the formula we have 1/30 = 1/v -1/4v

= 3/4v

v= 22.5cm

Above we had u = -4v

so -4× 22.5= -90cm

Hence distance of the object is - 90cm