Question

An upright object 1.75 cm tall is placed 38.0 cm to the left of a converging lens having a focal length f₁ = 28.0 cm. A converging lens of focal length f₂ = 18.0 cm is placed 108 cm to the right of the first lens.

(4points) Determine the final position of the final image.

(4 points) Determine the total magnification of the final image.

(3 points) Is the final image upright or inverted?

38.0 cm?? lens 2 lens 1

Please show all step when solving and show the formula if used.

Answer 1

lens1

object distance = d1o = 38 cm

image distance = d1i = ?

focal length f1 = 28 cm

1/d1o + 1/d1i = 1/f1

1/38 + 1/d1i = 1/28

d1i = 106.4 cm

magnification of converging lens m1 = -d1i/d1o = -2.8

for lens 2:
___________

object distance d2o = 108 - 106.4 = 1.6 cm

focal length f2 = 18 cm

1/d2o + 1/d2i = 1/f2

1/1.6 + 1/d2i = 1/18

image distance d2i = -1.76 cm

magnification m2 = -d2i/d2o = 1.76/1.6 = 1.1

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part A

image distance di = 1.76 cm

total magnification M = M1*M2 = -2.8*1.1 = -3.08

inverted