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Your telescope has a 700 mm -focal-length objective and a 24 mm -focal-length ey

ID: 1429976 • Letter: Y

Question

Your telescope has a 700 mm -focal-length objective and a 24 mm -focal-length eyepiece. One evening you decide to look at the full moon, which has an angular size of 0.52 when viewed with the naked eye.

What angle (in degrees) does the image of the moon subtend, when you look at it through your telescope? answer in degrees

Suppose you decide to take a photograph of the moon using your telescope. You position film so that it captures the image produced by the objective lens. What is the diameter of that image? answer in mm

Explanation / Answer

the angle subtended by image of the moon i s

theta = m theta_o

= (fo/ fe) theta_0

= 700/24 ) 0.52 = 15.16 degree

(b)

the the diameter of the image i s

angle = d/fo

d = fo * angle = 700 m * (0.52 * 3.14 / 180) = 6.34 mm