Question

Which of the of the following situations represents a positive displacement of carton? Assume positive position is measured vertically upward along a y-axis.
A. A delivery person waiting for an elevator lowers a carton onto a dolly
B. When the elevator doors open, the delivery person lifts the dolly over the threshold of the elevator
C. The delivery person pushes the dolly to the back of the elevator while pressing a floor button
D. The door closes and the elevator moves from the 10th to the 4th floors

Answer 1

Answer is B .
Thank you