An erect object is 25 cm from a concave mirror of radius 30 cm. The character of the image is? Solution R = 30 cm f = R/2 = 15 cm mirror equation: 1/f = 1/u + 1/v u = object distance = 25 cm v = image distance = ? f = focal length = 15 cm 1/v = 1/u - 1/f v = (1/25 - 1/15)^-1 v = -37.5 cm -ve sign means the image is real and inverted..