Question

If you have an object 2 m from the concave mirror and the image is 4 m from the mirror then f is __________​

Answer 1

Answer: f = -4

Explanation: u = -2(u is always -ve)

v = 4

f = ?

1/f = 1/v + 1/u

1/f = 1/4 + 1/-2

1/f = 1/4 + (-2/4)

1/f = 1/4 -2/4

1/f = 1-2/4

1/f = -1/4

f = -4