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Course: MCAT > Unit 3

Lesson 1: Foundation 4: Physical and chemical principles

Force and equilibrium: An elevator in a hospital


A hospital that specializes in orthopedic surgery and rehabilitation is investigating the accelerations experienced by patients while riding the hospital elevators so as to make sure they don’t cause pain to healing knees, ankles, and hips. To measure the acceleration of the elevators, the hospital placed a copper mass on an electronic scale that sat on the floor of the elevator.
The graph shown below is for a trial where the copper mass rides in the elevator from the bottom floor to the top floor. The elevator starts from rest, gets up to speed, travels upwards with constant speed, then slows down and stops at the top floor.
A similar trial was then conducted with a patient volunteer with knee arthritis. The patient stood on a scale in the elevator as it replicated the accelerative procedure. He then provided feedback on which portion of the journey was most physically taxing.
During the portion of the trip where the elevator is moving upwards with constant velocity, how will the scale reading compare to the weight of the copper?
Choose 1 answer: