Question

A 6-cm-high candle is placed in front of a converging lens with a focal length of magnitude 30 cm. If the image distance is +50 cm, then

find the image height of the candle and whether it is upright or inverted.

answer: 4cm, inverted

i need help understnading which eqution to use to complete this problem. Also could you explain how ot determine if an image is real, inverted, or upright? thank you will rate asap

Answer 1

1/f = 1/do + 1/di
do is distance between an object and a lens, the distance di between the lens and the image position, and the focal length f of the lens
-1/30 = -1/50 + 1/d0
do = -75
Since di is negative a VIRTUAL image would be formed in front of the lens on the same side the object is placed.

magnification M = -di / do = hi/ho

hi=4

When an object is located inside of the focal point of a converging lens, the image will be virtual, upright, larger than the object and located on the same side of the lens as the object