Question

An object that is 4.00 cm tall is placed 18.0 cm in front of a concave mirror having a focal length of 25.0 cm.

a. What is the location of the image?

b. What is the magnification of the image?

c. Is the image inverted or upright?

d. Is the virtual or real

Answer 1

Given h image = 4 cm, u = -18 cm and f = -25 cm (negative because it is a concave focal length)

To find the location of the image, we will use the mirror formula,

1/v + 1/u = 1/f

1/v = 1/f - 1/u

1/v = 1/18 - 1/25

v = 64.28 cm

b) Magnification of the image,

m = v/u

Putting the values, we have

m = -64. 28/18 = -3.57

c) As magnification is negative, hence the image must be inverted.

d) As the image is inverted, it has to be real.