Final answer:
The relative velocity of the car with respect to the truck is 12 mph, which is found by subtracting the truck's velocity (45 mph) from the car's velocity (57 mph).
Step-by-step explanation:
The question is about finding the relative velocity of two vehicles moving in the same direction on a highway. To calculate the relative velocity of the car with respect to the truck, you subtract the velocity of the truck from the velocity of the car.
Since the truck has a speed of 45 mph and the car has a speed of 57 mph, the relative velocity is the difference between the two speeds.
To find the relative velocity:
- Relative Velocity of car with respect to truck = Speed of car - Speed of truck
- Relative Velocity = 57 mph - 45 mph
- Relative Velocity = 12 mph
So, the car is moving at a relative velocity of 12 mph with respect to the truck.