Question

an object of height 7.5 cm is placed in front of a convex mirror of radius of curvature 25cm at a distance of 40 cm the height of the image should be

Answer 1

Object height (h) = +7.5 cm
Radius of curvature (R) = +25 cm
Object distance (u) = -40 cm
Image height (h') = ?

Now, focal length (f) = R/2
f = +12.5 cm

By using the mirror formula,
1/f = 1/v + 1/u
1/v = 1/f - 1/u
1/v = 1/12.5 - (1/-40)
1/v = 21/200
v = 200/21 cm

Now, h'/h = -v/u
h' = -vu/h
h' = +50.79 cm
Height of the image= 50.79 cm