Answer: 20 m/s
Step-by-step explanation:
First of all, we can calculate the acceleration of the car by using Newton's second law:

where F is the net force on the car, m is the mass, a is the acceleration. Using m=1000 kg and F=2000 F, we find the acceleration

The acceleration is also equal to the ratio between the change in velocity and the time taken:

Since we know the time taken,
, we can re-arrange the formula to find the change in velocity of the car:
