Answer:
The net displacement of the car is 3 km West
Explanation:
Please see the attached drawing to understand the car's trajectory: First in the East direction for 4 km (indicated by the green arrow that starts at the origin (zero), and stops at position 4 on the right (East).
Then from that position, it moves back towards the West going over its initial path, it goes through the origin and continues for 3 more km completing a moving to the West a total of 7 km. This is indicated in the drawing with an orange trace that end in position 3 to the left (West) of zero.
So, its NET displacement considered from the point of departure (origin at zero) to the final point where the trip ended, is 3 km to the west.
The line that should be secured first in pushing the boat
away from the dock in preparation to dock is the bow line. When the bow line is
secured, it is best to reverse it and turn to the dock, this will engage the
line to tighten in a way that will help it swing back in the dock.