You look at yourself in a shiny Christmas tree ball, which has a diameter of 9.63 cm. If your face is 7.81 cm away from the shiny ball, calculate the image distance.
Thinking I would use
magnification = di/d0
di = 0.0781m
d0 = 0.0963m
The Attempt at a Solution
This doesn't sound right to me, is this perhaps because di is supposed to be what I'm trying to find out???
If so, would I then assume that the magnification is 0.0781 and I need to times that by 0.0963 to work out di? The the calculations would be as follows;???
m x do = di
di = 0.0781 x 0.0963
= 7.52 x 10^-3 m (3sf)
I think this would be the correct way to work out this question, I just wanted to double check that my second method is correct???