A body of mass is supported by a spring balance attached to the ceiling of an elevator
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
A body of mass m is supported by a spring balance attached to the ceiling of an elevator. With the help of a free-body diagram, derive an expression for the reading R of the balance when the elevator is accelerating uniformly with magnitude a. An elevator starts from rest and descends 25m in 5.0s. It accelerates uniformly during the first half of the distance and decelerates uniformly during the second half, coming to rest at the lower floor. A person of mass 60kg stands on the balance throughout the journey.
(a) (i) upward, (ii) downward.
(b) (i) Calculate the magnitude of the acceleration during the first half and during the second half. (ii) Determine the maximum and the minimum readings shown by the balance in the entire trip. (iii) Sketch (qualitatively) the variation of the apparent weight with time for the complete motion.