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In an experiment to monitor the Moons surface with a light
Chapter , Problem 92(choose chapter or problem)
In an experiment to monitor the Moons surface with a light beam, pulsed radiation from a ruby laser (l ! 0.69 mm) was directed to the Moon through a reflecting telescope with a mirror radius of 1.3 m. A reflector on the Moon behaved like a circular flat mirror with radius 10 cm, reflecting the light directly back toward the telescope on Earth. The reflected light was then detected after being brought to a focus by this telescope. Approximately what fraction of the original light energy was picked up by the detector? Assume that for each direction of travel all the energy is in the central diffraction peak.
Questions & Answers
QUESTION:
In an experiment to monitor the Moons surface with a light beam, pulsed radiation from a ruby laser (l ! 0.69 mm) was directed to the Moon through a reflecting telescope with a mirror radius of 1.3 m. A reflector on the Moon behaved like a circular flat mirror with radius 10 cm, reflecting the light directly back toward the telescope on Earth. The reflected light was then detected after being brought to a focus by this telescope. Approximately what fraction of the original light energy was picked up by the detector? Assume that for each direction of travel all the energy is in the central diffraction peak.
ANSWER:Problem 92
In an experiment to monitor the Moon's surface with a light beam, pulsed radiation from a ruby laser () was directed to the Moon through a reflecting telescope with a mirror radius of 1.3 m. A reflector on the Moon behaved like a circular flat mirror with radius 10 cm, reflecting the light directly back toward the telescope on Earth. The reflected light was then detected after being brought to a focus by this telescope. Approximately what fraction of the original light energy was picked up by the detector? Assume that for each direction of travel all the energy is in the central diffraction peak.
Step by Step Solution
Step 1 of 3
Let’s take the Earth-Moon separation as . The energy of the beam of light that is projected onto the Moon is concentrated in a circular spot of diameter , where , with the diameter of the mirror on Earth. The fraction of energy picked up by the reflector of diameter on the Moon is then