Question

an object of length 2.5 CM at a distance of 1.5 f from a concave mirror when f is the magnitude of the focal length of the mirror find the length of the image and nature of the image​

Answer 1

Focal length F=−f

and u=−1.5f

1u+1v=1F

1−1.5f+1v=−1f

1v=11.5f−1f

=−−13f

v=−3f

Now m=−vu=−3f1.5f=−2

or h2h=−2

or h2=−2h1=−5cm

the image is 5 cm long.

The minus sign shows that it is inverted.