Answer:
8000Ns
Step-by-step explanation:
Given parameters: 
Mass of the truck = 1000kg 
Initial velocity = 9m/s 
Final velocity = 17m/s 
Unknown: 
Impulse = ? 
Solution: 
The impulse experienced by the truck is the the change in momentum of the body. 
 Impulse = Ft 
 Momentum = m(v - u)
 Ft = m( v - u )
 F is the force 
 t is the time 
 m is the mass
 v is the final velocity 
 u is the initial velocity 
 Impulse = 1000(17 - 9) = 8000Ns