1) Impulse: -32,000 kg m/s
The impulse acting on the car is equal to the change in momentum of the car:
where in this problem we have
m = 1000 kg is the mass of the car
v = 0 m/s is the final velocity of the car
u = 32 m/s is the initial velocity of the car
Substituting values into the equation, we find
2) -4751 N
The impulse exerted on the car is also equal to the product between the average force, F, and the duration of the collision, t:
where in this situation we know
is the impulse
t = 7 s is the duration of the collision
Solving the formula for F, we find the average force:
and the negative sign means that the force is in the opposite direction to the motion of the car.