Final answer:
To compare the speeds of Car A and Car B at t=1 s, we need velocities at that specific time. Car A's speed is known to be 15 m/s, but without Car B's speed at t=1 s or a descriptive equation of its motion, a comparison cannot be made.
Step-by-step explanation:
To determine if the speed of Car A is greater than, less than, or equal to the speed of Car B at t=1 s, we must examine their respective velocities at that instant. Given that c. Magnitude of instantaneous velocity is equal to instantaneous speed, and the information provided, "d. At t= 1 s, velocity v(1 s) = 15 m/s is positive and acceleration is positive, so both velocity and acceleration are in the same direction. The particle is moving faster," indicates that the speed (which coincides with the magnitude of velocity) is indeed 15 m/s for Car A.
Unfortunately, we are not provided with enough information about Car B's velocity at t=1 s to make a direct comparison. If we assume Car B's information is somehow related to the previous data points such as (b) 12 m/s or (c) 3 m/s², there's nothing that specifies Car B's speed at t=1 s. To give a conclusive answer, we would need either the velocity of Car B at t=1 s or a functional relationship describing Car B's motion.
Without this additional data for Car B, any comparison would be conjecture. Therefore, we cannot determine if Car A's speed is greater than, less than, or equal to Car B's speed at t=1 s with the information provided.