A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three times the size of the object?
- 12cm
-
24cm
- 48cm
- 108cm
The correct answer is: B
Explanation
F = \(\frac{uv}{u + v}\)v = 3u
18 = \(\frac{3u \times u}{3u + u}\)
u = 24cm