Question

An image of an object placed in front of a convex mirror formed 8 cm away. If the focal length of the mirror is 16 cm, calculate the distance of the object from the mirror.

Answer 1

Answer:

u= -16

length of object is always negative.

Explanation:

object image  =v= -8cm

focal length= f= -16cm

so, applying mirror formula,

1/f = 1/v + 1/u

1/-16 = 1/-8 + 1/u

-1/16 + 1/8 = 1/u

Taking LCM,

-1+2/16 = 1/u

1/16 = 1/u

RECIPROCALING,

SO, u= -16

length of object is always negative

Answer 2

Answer:

Explanation:

object image  =v= -8cm

focal length= f= -16cm

so, applying mirror formula,

1/f = 1/v + 1/u

1/-16 = 1/-8 + 1/u

-1/16 + 1/8 = 1/u

Taking LCM,

-1+2/16 = 1/u

1/16 = 1/u

RECIPROCALING,

SO, u= -16

length of object is always negative