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## Homework Statement

Suppose you wanted to be able to see astronauts on the moon. What is the smallest diameter of the objective lens required to resolve a 0.60 m object on the moon? Assme the wavelength of the light is near the middle of the visible spectrum: 550 nm yellow light.

(in m)

**A**: 4.25×10^2

**B**: 4.97×10^2

**C**: 5.82×10^2

**D**: 6.81×10^2

**E**: 7.96×10^2

**F**: 9.32×10^2

**G**: 1.09×10^3

**H**: 1.28×10^3

## Homework Equations

Rayleigh's Criterion:

=> θ1 = 1.22λ/D

=> w = (2.44*λ *L)/D

w is width; L is length from screen to object.

## The Attempt at a Solution

So I know we are calculating the diameter of the lens needed so I solved the equation for D and got:

w = (2.33*λ *L)/D

after this step I converted all my values to meters and got: these values:

(2.44*5.5E-7m*3.97E8m) / 0.6m = 888.6m which is in the range I need but It has to be an exact answer.

Can anyone help me understand what I did wrong?

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