Physics Review Question Unit: mechanics Year: 1989 Question#: 9 Question: An unbalanced 6.0-newton force acts eastward on an abject for 3.0 seconds. The impulse produced by the force is (1 ) 18 N s east (2 ) 2.0 N s east (3 ) 18 N s west (4 ) 2.0 N s west What is this question really asking? Explanation by: Allison B. [ Return to question menu ] Answer 1 18 N s east CORRECT Impulse is the change in momentum of an object. It is calculated by multiplying the force applied by the amount of time it is applied. p=F t so: p= 6.0N (east) 3.0 seconds = 18 N Ą s east return to top Answer 2 2.0 N s east INCORRECT this answer was obtained by using the wrong formula: p = F/t the correct formula is p = F t return to top Answer 3 18 N s west INCORRECT Impulse is a vector (it has direction). This answer was obtained using the correct formula, but the wrong direction. return to top Answer 4 2.0 N s west INCORRECT This answer was obtained using an incorrect formula: p = F/t. The correct formula is p = F t . In addition, impulse is a vector, and this answer has the wrong direction. return to top What's this question really asking? It's asking if you understand what an impulse is and how to calculate it. 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.