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.

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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 t
so: 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/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

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