(Force x Distance) Magnitude of velocity help

[Barukun]

Homework Statement

A 2KG mass has been graphed to increase in force after 3 meters east to 4 Newtons. it maintains 4 Newtons for 2 more meters east and then decreases back to 0 after 7 meters
..._
_/..\__...__ shape graph. I am trying to find out its magnitude of velocity at 7.4 Meters.
...^.|_|

Around about where the arrow is. (ignore the . they are just placeholders to try and show the graph shape)

Homework Equations

1/2 MV^2

The Attempt at a Solution

I already know the answer, i am trying to do the workings out. It equals 4.2 M/s

 

[gneill]

You've got forces and distances that they are applied. Looks like you should be able to calculate the work done for each distance segment. You'll have to concoct suitable expressions for the force with respect to distance for the segments where the force is changing.