Impulse and Force-Time Graph Problem

[jmm]

Homework Statement

In the figure , what value of Fmax gives an impulse of 7.1 Ns

Homework Equations

The Attempt at a Solution

Impulse is the integral of force with respect to time which is the same the area under the force-time graph which is given by the area of the triangle: 0.5*Fmax*8s

7.1 Ns = 4s * Fmax
Fmax = 1.775 N

However that's not the right answer. Where did I go wrong? Thanks!

 

[cepheid]

The time axis is in milliseconds.

 

[jmm]

Haha thanks! I never would've noticed that.