an object of 1 cm produce areal image of 1.5.cm of high when placed at adistance of 15cm from concave mirror calculate the position of the image and the focal lenght of the concave mirror

45 cm

Explanation:

Formula = h' u / h = v

- v = (1.5) (-15) / 1

- v = - 22.5

v = 22.5

The image is positive, therefore it is a virtual and erect image.

∴ the image is formed at a distance of 22.5 cm behind the mirror.

1 / v + 1 / u = 1 / f

1 / f = 1 / 22.5 + 1 / (- 15)

1 / f = 1 / 22.5 -1 / 15

1 /f = (15 - 22.5) / 337.5

1 / f = -7.5 / 337.5

f = 337.5 / - 7.5

f = - 45 cm

∴ the focal length of the mirror is 45 cm.

it is called kinetic energy