Answer:
The velocity
Explanation:
The difference between speed and velocity is the following:
- Speed is defined as the ratio between the total distance covered by an object and the time taken:
and it is a scalar.
In this problem, we cannot calculate the speed of the car, because we don't know exactly what is the distance covered by the car (we only know the distance between town A and town B, but we don't know if the car has travelled on a straight path or not, so we don't know the distance it has covered)
- Velocity is defined as the ratio between the displacement and the time taken:
(note that velocity is a vector)
Displacement is the shortest distance (straight line) between the final and the initial point of the motion: in this case, it corresponds to the distance between town A and town B, which we know. Since we also know the time of the trip, this means that we can calculate the velocity of the car.