The image of an object is located 6cm behind a convex mirror. If it's magnification is 0.6, calculate the focal length of the mirror

A.

3.75cm

B.

6.70cm

C.

10.00cm

D.

-15.00cm

Correct answer is D

V = -6cm

M = 0.6cm

Recall m = \(\frac{V}{U}\)

U = \(\frac{V}{M}\)

U = \(\frac{6}{0.6}\)

 U = 10

  \(\frac{1}{U}\) + \(\frac{1}{V}\) = \(\frac{1}{F}\)

 \(\frac{1}{10}\) + \(\frac{1}{-6}\) = \(\frac{1}{F}\)

\(\frac{-4}{60}\) = \(\frac{1}{F}\)

 F = \(\frac{60}{-4}\)

=  -15cm