Question

In a concave mirror of focal length 15cm,if the image formed is three times the size of the Object,then the position of the Object is​

Answer 1

Answer:

-20

Explanation:

$given \: that \\ f = - 15cm \\ m = - 3 \\ we \: know \: mirror \: formula \: as \\ m = f \div (f - u) \\ - 3 = - 15 \div ( - 15 - u) \\ - 15 - u = 5 \\ so \: \: \: \: \: u = - 20$