Physics Review Question Unit: Mechanics Year: 1989 Question#: 14 Question: Gravitational force of attraction F exists between two masses A and B when they are separated by a fixed distance. After mass A is tripled and mass B is halved, the gravitational attraction between the two masses is: (1 ) 1/6 F (2 ) 2/3 F (3 ) 3/2 F (4 ) 6 F What is this question really asking? Explanation by: JD W. [ Return to question menu ] Answer 1 1/6 F INCORRECT Mass A has been tripled. So the force from A to B is increased 3 times. Mass B has been decreased by a half, so that increases the force between mass A and B by 1/2 so the force would not be1/6 F return to top Answer 2 2/3 F INCORRECT Mass A has been tripled. So the force from A to B is increased 3 times. Mass B has been decreased by a half, so that increases the force between mass A and B by 1/2 so therefore the answer is not 2/3 F. return to top Answer 3 3/2 F CORRECT Nice use of the formula . Mass A has been tripled. So the force from A to B is increased 3 times. Mass B has been decreased by a half, so that increases the force between mass A and B by 1/2 Combining the tripling and the halving you would get half of 3 which would look like (3/2) F return to top Answer 4 6 F INCORRECT Mass A has been tripled. So the force from A to B is increased 3 times. Mass B has been decreased by a half, so that increases the force between mass A and B by 1/2 so the answer could not be 6 F. return to top What's this question really asking? This question is basically asking about gravitational force. If the initial force was equal, then mass A was tripled and mass B was decreased by half, what's the force of attraction now? return to top This web site is designed and maintained by Science Joy Wagon and may not be reproduced or redistributed without written permission from Science Joy Wagon. Contact with comments.