# a) What will an object weigh on the Moon's surface if it weighs 170 N on Earth's surface?

b) How many Earth radii must this same object be from the center of Earth if it is to weigh the same as it does on the Moon?

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It was Sir Isaac Newton who had first calculated the Earth-Moon neutral point using his theory of gravitation. That theory gave him an average Earth- Moon distance of 238,900 miles, and the neutral point thus occurred at ~ 23,900 miles from the moon(1). This of course gave the familiar figure that the Moon's gravitational attraction was about 1/6th that of Earth.

But then came a 1969 edition of Time magazine, an interview with Werner Von Braun himself, and the beginning of a persisting mathematical mystery concerning the Earth-Moon dual planetary system. Time reported that "43,495 miles from the Moon lunar gravity exerted a force equal to the gravity of the Earth, then some 200,000 miles distant." If this neutral point figure is correct, then the Moon is much more massive than any standard view of celestial mechanics will allow. A mere two weeks after the Time magazine article, Werner Von Braun quite suddenly resigned all his NASA posts and took a position as Vice President for Fairchild Industries. At minimum it began a process of "arithmetical obfuscation", that can only be seen as deliberate, since to view what happened next as NOT being deliberate would be akin to charging NASA with gross mathematical incompetence. For example, in the 1981 edition of Baker's Space Technology, the Apollo 11 distance to the Moon is given as 253,475 miles. But in the book Apollo 11 Moon Landing gave the distance as just under 250,400 miles. Then in 1996 Baker's Spaceflight and Rocketry gave the neutral point as 38,925 miles from the Moon and 214,550 miles from the Earth, giving a total distance to the Moon of 253,475 miles. To confound matters even further, space experts at NASA or elsewhere do not state whether they are using surface to surface, or center to center measurements. Nor do they state whether they are using nautical miles or statute miles. Nor do they stick to any one system. In short, "the only consistency in the Earth- Moon measurement scenario is the inconsistency of the data emanating from official sources." Percy and Bennet's way out of this impasse is to posit that the 23,900 mile figure, the Newtonian figure. is correct, and that the figure revealed by Von Braun to Time magazine is the "experienced" neutral point. Talk about double talk! In summo with a neutral point 43,495 miles, the gravity of the Moon would be a whopping 60% that of Earth! So considering celestial mechanics here my answer would be .6*170N = 102 N

Source(s): (1) Dark Moon , Mary Bennet and David S Percy, p. 392 The SS Brotherhood of the Bell; Joseph P Farrell, p. 126,127
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• the item Weight is given with 2 formula: W= m g and W= g M m / r² from this formula we come across the earth mass : M = W r² / g m the place r is the area of the item from the midsection of the earth whilst it is on the floor and is comparable to r whilst the item is at top r from the floor we've obejct distance from midsection of the earth to the item would be r+r = 2r So Wr at top r is: Wr= g Mm / (2r)² so if we take M from the 2d formula we've Wr = g W r² m / gm (2r)² = W r² / 4 r² = W /4 = 200 / 4 = 50 N

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• I guess it wud weigh 28.33 N, to convert it simply divide it by 6, as monn‘s gravity is 1/6 of earth

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