A runner completes one full lap around a 400 meter track. What is her
displacement?
Zero, unless she runs in an outer staggered lane. In that case she does not start at the finish line.
Zero. She finished where she started, therefore no displacement, or change in postion.
To determine the displacement of the runner, we need to consider the starting and ending points of her motion. Displacement is a vector quantity that represents the change in position from the starting point to the ending point, in a straight line.
In this case, the runner completes one full lap, which means she starts and ends at the same point on the track. Therefore, her displacement is zero.