The figure shows a combination of two lenses. (Figure 1)
- Find the position of the final image of the 1.0 cm tall objects.
- Find the size of the final image of the 1.0-cm-tall objects.
Answer: THIS ANSWER WASN’T REVIEWED BY OUR EXPERTS!
1/f = 1/o = 1/di
find di of 1st lens
1/5 = 1/4 + 1/di
di = -20 cm (to left of 1st lens)
this plus distance between lenses is now the do for 2nd lens
20 + 12 = 32
then
1/-8 = 1/32 + 1/di
di = -6.4 cm
so final image is 6.4 cm LEFT of the 2nd lens [[1st answer]]
Find magnification of both lenses
M = – do/di
M1 = – (-20 / 4) = +5
M2 = – (-6.4 / 32) = +0.2
overall M is this product
M = M1 * M2 = 5 * .0.2 = 1
so the final image is the same size as the 1st object
summary
we have an upright image, 1.0 cm tall at 6.4 cm left of the 2nd lens.
