Question

plz ans fast .......................

Answer 1

Object-size, h = + 5.0 cm;
Object-distance, u = – 20.0 cm;
Focal length, f = –15.0 cm;
Image-distance, v = ?
Image-size, h′ = ?
Mirror formula is (1/v) + (1/u) = 1/f

1/v = (1/f) − (1/u)
= (−1/15) + (1/20)
= −1/60
v = − 60 cm.

The screen should be placed at 60 cm from the mirror. The image is real.

Magnification m = h'/h = − v/u = 60/(– 20) = – 3

Height of the image h' = mh = (– 3)x5 = − 15 cm