How to Calculate Image Position and Magnification for a Camera Lens?

[GoodOldLimbo]

Homework Statement

A camera lens has focal length 55mm and an object is 500mm away. Calculate the position of the image and the magnification (or reduction)

Homework Equations

1/u + 1/v = 1/f

u = Object Distance

v = Image Distance

f = focal length

m = magnification

The Attempt at a Solution

f = 55

u = 500

1/500 + 1/v = 1/55

1/55 - 1/500 = 1/v

55^-1 - 500 ^-1 = 0.01618

ANS^-1 = 61.79 so approximately 62mm

v/u = m

62/500 = 0.124M

Did I go with the right approach? Any help would be great.

 

[paisiello2]

Looks OK to me.

The only things I can think of is that the magnification M = -0.124

1) magnification is supposed to be -ve because the image is usually upside down after the light rays go through a lens provided the object is outside the focal length

2) 0.124M should just be 0.124 since it is a dimensionless number.