# sol11 - 29 29 2 2 2 2 1 2 1 1 2 2 2 4 4 4 20 N 80 N new new...

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PHYSICS 103 Chapter 5 -- HW #11 Questions 4. According to Newton's third law the force the Earth exerts on the satellite is the same size and the opposite direction as the force the satellite exerts on the Earth. Therefore, the satellite exerts a force of 10,000 newtons upward on Earth 12. Because the range of the force of gravity is infinite, the spacecraft never "leaves" the gravitational force of the Earth. The commentator meant that the Moon's attraction for the spacecraft was now stronger than the Earth's attraction for the spacecraft. Exercises 6. We know that the force gets weaker as the distance between the objects gets larger. In this case, the spacecraft are closer together, so the force must get stronger. We also know that the force varies as the square of the distance. Since the distance changes by a factor of two, the force must change by a factor of two squared, or four. Therefore, the new force is 4 x 20 N = 80 N. We can also do this problem by taking the ratio of the two forces.
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Unformatted text preview: ( 29 ( 29 2 2 2 2 1 2 1 1 2 2 2 4 4 4 20 N 80 N new new new old old old old old old new new old new old F m m r r r F m m r r r F F = = = = = ÷ ÷ ÷ ÷ ÷ = = = 8. Because the gravitational force is directly proportional to the mass of each of the interacting objects, cutting the mass of one of the objects in half cuts the force between them in half. Cutting the mass of the other object in half, cuts the force in half again. Therefore, the force is one-fourth as strong, or (50 N)/4 = 12.5 N. Using our formulas we have ( 29 2 1 1 1, 2, 2 2 1 2 1 2 1, 2, 1 1 4 4 1 4 50 N 12.5 N old old new new new old old old old new old old new old m m F m m r F m m r m m F F = = = ÷ ÷ ÷ ÷ ÷ = = =...
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## This document was uploaded on 10/29/2011 for the course PHSX 103 at MSU Bozeman.

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