For many years,the Palomar telescope (5-m diameter)in California was the largest telescope in the world; it has now been surpassed by both Keck telescopes (each of diameter 10 m)in Hawaii.How much greater is the light-gathering power of a Keck telescope than that of the Palomar telescope?
A) 4 times greater
B) 8 times greater
C) 2 times greater
D) 1.4 times greater

Question

Quizplus · Accepted Answer

The light-gathering power of a telescope is proportional to the area of its aperture, which is proportional to the square of the diameter. The Keck telescope has a diameter of 10 m, and the Palomar telescope has a diameter of 5 m. The ratio of their light-gathering powers is (10/5)^2 = 4.

For Many Years,the Palomar Telescope (5-M Diameter)in California Was the Largest