Final answer:
The final speed of the car is twice as much as that of the truck because it accelerates for twice the length of time, assuming it starts from rest and both have the same rate of acceleration.
Step-by-step explanation:
If a car and a delivery truck accelerate at the same rate, but the car accelerates for twice the time, the final speed of the car is twice as much as that of the truck. This is because the final velocity is determined by the formula v = u + at, where v is the final velocity, u is the initial velocity (which is zero in this case), a is the acceleration, and t is the time. Since the acceleration is the same for both vehicles, and the car accelerates for twice as long, it will reach a final speed that is twice that of the truck's final speed.