You are asked to design a shaving mirror assuming that a person keeps it 10 cm from his face and views the magnified image of the face at the closest comfortable distance of 25 cm. The radius of curvature of the mirror would then be

Answers (2)
S safeer

 From question v = 15 cm,  u = -10 cm

Radius of curvature R = 2f = ?

Mirror formula \frac{1}{v}+\frac{1}{u}=\frac{1}{f}=\frac{1}{15}+\frac{1}{(-10)}=\frac{1}{f}

 f = - 30 cm

\therefore    R= 2(-30) = - 60 cm