Question

a concave mirror of focal length 10 cmis placed at a distance of 35 cm from wall. how far from the wall an object be placed so that image formed by the mirror falls on the wall?

Answer 1

Heya

Here goes your answer

According to your question, the final length of the concave mirror is 10cm and the image should be formed on the wall i.e the image distance is 35cm.

We are needed to find the object distance.

Using 1/f=1/v+1/u

1/10=1/35+1/u

1/10-1/35=1/u

(35-10)/350=1/u

25/350=1/u

1/14=1/u

u=14cm

◆ The object should be placed 14cm before the concave mirror to get the image on the wall.