Question

A concave mirror has a focal length of 19 cm. The mirror forms an image located 31 cm in front of the mirror. What is the magnification of the mirror?

Answer 1

Given:

A concave mirror has a focal length of = F = 19 cm

This mirror forms an image located = V = 31 cm

(in front of the mirror)

magnification of the mirror= M = ? (Include the sign.)

It is known by the formula mirror

1/ F = 1/U + 1/V

where U is the distance of the object form mirror = U = ?

thus, F V / V - F = U

             (19)(31) /31- 19 = 49.08 cm

   thus, U = 49.08cm

Magnification of the concave mirror = M = - V / U

        = - 31 cm / 49.08 cm = - 0.632

   thus, magnification = M = - 0.632