Question

what is magnification? an object of 5cm in length is placed at a distance of 20cm in front of convex mirror of radios of carvature 30cm

Answer 1

given r=30
therefore f=15 cm
u=20 cm
$\frac{1}{u} + \frac{1 }{v} = \frac{1}{f}$
1/-20+1/v=1/15
1/v=1/15+1/20
1/v=20+15/300
1/v=35/300
1/v=7/60
v=60/7
$m = \frac{ - v}{u}$
$- \frac{60}{7} \div - 20$
m=3/7