Find the minimum aperture diameter of a camera that can resolve detail on the ground the size of a person (2.0 m ) from an sr-71 blackbird airplane flying at an altitude of 29 km . (assume light with a wavelength of 450 nm .)

Minimum aperture diameter, B =

Given:

Altitude of airplane, l = 29 Km = 29000 m

width, d = 2.0 m

wavelength,

Solution:

By Reighley criterion, Angle of resolution is given by:

                           (1)

Also, separation angle or limiting angle,        (2)

From eqn (1) and (2):

B = 7.96 mm

there are no contact forces mentioned on the list of choices that you've provided.