JAMB - Physics (2009 - No. 22)
Calculate the position of an object placed in front of a convex mirror having focal length of 12 cm such that an image is formed 6 cm away from the mirror
4. 0 cm
3. 0 cm
12.0 cm
9.0 cm
Giải thích
f = -12 cm, v = - 6 cm
(1)/v + (1)/u =(1)/f
(1)/-6 + (1)/u = (1)/-12
(1)/u = (1)/-12 + (1)/6 = (1 + 2)/12 = (1)/12
∴ u = 12 cm
(1)/v + (1)/u =(1)/f
(1)/-6 + (1)/u = (1)/-12
(1)/u = (1)/-12 + (1)/6 = (1 + 2)/12 = (1)/12
∴ u = 12 cm