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Unformatted text preview: lai (yl8859) HW19 Ross (15200) 1 This print-out should have 6 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points How high does a rocket have to go above the Earths surface so that its weight is reduced to 64 . 9% of its weight at the Earths sur- face? The radius of the Earth is 6380 km and the universal gravitational constant is 6 . 67 10 11 N m 2 / kg 2 . Correct answer: 1539 . 51 km. Explanation: Let : W r + h = 0 . 649 W r . The weight of the rocket is equal to the gravitational force acting on the rocket, so W = F 1 r 2 and W r W r + h = ( r + h ) 2 r 2 r + h = r radicalBigg W r W r + h h = r parenleftBigg radicalbigg W r . 649 W r- 1 parenrightBigg = (6380 km) parenleftBigg radicalbigg 1 . 649- 1 parenrightBigg = 1539 . 51 km 002 (part 1 of 2) 10.0 points On the way to the moon, the Apollo astro- nauts reach a point where the Moons gravi- tational pull is stronger than that of Earths.tational pull is stronger than that of Earths....
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This note was uploaded on 02/24/2011 for the course PHYS 152 taught by Professor Button during the Winter '08 term at IUPUI.
- Winter '08