A person on the second floor takes the elevator up 5 floors, crosses to the other side of the building then takes the elevator on that side down by 2. The height of each floor is 3.5 m and the width of the building is 21 m. What is the person's displacement?

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.