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.
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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 tso:
p= 6.0N (east) 3.0 seconds= 18 N ¥ s east return to top
Answer 2
2.0 N s east
INCORRECT
this answer was obtained by using the wrong formula:
p = F/tthe 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
