A car travels for 15-s at a velocity of 12m/s due north. What is the displacement of the car?
Displacement: 180 m
To determine the car's displacement, you need to take into account its starting point and finish point.
Since your car travels in a straight line and in one direction, i.e. it maintains a constant direction throughout its motion, its displacement will actually be equal to the total distance it covered.
To get the total distance the car covered during its trip, use the fact that you know how much distance is covered in a second, i.e. the car's velocity, and the total time needed to reach its destination