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captainjack2000
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Homework Statement
Two red lights are separated by 5cm, perpendicular to your line of sight. How far away from them are you if they can just be resolved with the naked eye?
Homework Equations
angular resolution =sin(theta)=1.22lambda / D
spatial resolution = 1.22(focal length * lambda)/D
The Attempt at a Solution
the angular resolution of the eye is about 1 min of arc = 1/60th of a degree
the wavelength of red light is about 650nm
In the equation above D is diameter of the eye's pupil - approximately 5mm?
spatial resolution=5cm
I am not quite sure how to put all this information together?
using the information I have;
5cm=1.22(focal length *650nm)/5mm
which gives the focal length of 315 m