#### Answer

Since the impulse is equal to the area under the graph, the force exerts an impulse of $4~N~s$ on the particle.

#### Work Step by Step

The impulse is equal to the area under the force versus time graph. We can find the area under the graph.
$Area = (1000~N)(2\times 10^{-3}~s)+\frac{1}{2}(1000~N)(4\times 10^{-3}~s)$
$Area = 4~N~s$
Since the impulse is equal to the area under the graph, the force exerts an impulse of $4~N~s$ on the particle.