C) 9 kilogram meters/second
Explanation:
The impulse is defined as the integral of the force over the time:
[tex]J=\int F dt[/tex]
in a force-time graph, the impulse corresponds to the area under the curve. Therefore, in this case we can calculate the impulse by finding the area of the triangle.
The base is 3 s, while the height is 6 N, therefore the area (and the impulse) is
[tex]J=\frac{(3 s)(6 N)}{2}=9 kg m/s[/tex]
