Question 6
Along a straight path, a child travels 60 m from A to B. They then travel a further 40 m in the same direction, arriving at C. What is the child's total displacement?
The right answer is the one marked above.
100 m. Both displacements lie in the same direction, so they can be added with ordinary arithmetic:
total displacement = 60 m + 40 m = 100 m
The child is now 100 m from the starting point in a straight line. Here the distance travelled is also 100 m, because the direction never changed. 20 m comes from subtracting instead of adding.