Question
Fri December 16, 2011 By: Anirudh Venkat

THE WEIGHT ON THE MOON IS ONE - SIXTH THAT OF THE EARTH. WHAT IS THE PROOF FOR IT. WHETHER g VALUE DECREASES. HOW WE CAN CALCULATE THAT THE VALUE OF g IS DECREASED FROM THE EARTH SURFACE TO CERTAIN HEIGHT

Expert Reply
Mon December 19, 2011
Surface gravity is determined by mass and radius. The moon is 0.01230 times the Earth's mass and 0.2725 times the Earth's radius. Since gravity is proportional to mass divided by distance squared, the ratio of the Moon's surface gravity to that of the Earth is,

0.01230 / 0.2725^2 = 0.1656

or approximately 1/6th.
 
Since gravity is inversely proportional to the distance from the center of the object to the center of the earth. Therefore, as we increase height, gravity of the Earth will decrease. 
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