It's gonna crash!

In a crash test, a $$1.5$$ metric ton vehicle collides a brick wall. The initial velocity of the vehicle is $$v_{i}=-10\text{ m/s}$$ while its final velocity is $$v_{f}=2.6\text{ m/s}$$. If the collision lasts for $$0.2$$ seconds, what is the average force (in Newtons) exerted on the vehicle due to the collision?