Final answer:
To make a 6.0 m-long car appear only 5.5 m long, it would need to be moving towards you at a speed of 0.5 m/s.
Step-by-step explanation:
In order to calculate the speed at which a 6.0 m-long sports car would appear to be only 5.5 m long, we can use the concept of relative velocity.
The car would need to be moving towards you at a speed of 0.5 m/s so that the difference in length (6.0 m - 5.5 m) is covered while the car is passing by you.