Q. 154.5( 8 Votes )

A person is standing on a weighing machine placed on the floor of an elevator. The elevator starts going up with some acceleration, moves with uniform velocity for a while and finally decelerates to stop. The maximum and the minimum weights recorded are 72 kg and 60 kg. Assuming that the magnitudes of the acceleration and the deceleration are the same, find (a) the true weight of the person and (b) the magnitude of the acceleration. Take g = 9.9 m/s2.

Answer :


Let actual weight of the person be


Given:


Maximum weight


Minimum weight


When the elevator moves with acceleration , a pseudo force acts on the person in the downward direction.


In this case the weight is maximum as measured by the weighing machine, -----(1)


Where is the acceleration of the elevator.


When the elevator moves with deceleration , a pseudo force acts on the person in the upward direction.


In this case the weight is minimum as measured by the weighing machine, -----(2)


Adding (1) and (2) we get,



Thus, the weight


Subtracting (2) from (1)



Thus, the magnitude of acceleration,



Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Pseudo Force52 mins
Challenging Quiz on Newton Laws of Motion Part 364 mins
Pully Problems | Getting JEE Ready68 mins
Check your understanding of linear momentum22 mins
Why edges are raised for Curved roads? - Banking of roads54 mins
Into the world of springs - Spring force48 mins
Basics strengthener - Newton Laws of motion61 mins
Understand Newton's 2nd law Exhaustively34 mins
Elaborative Lecture on Constraint Motion59 mins
Escaping the reality - Concept of Pseudo Force54 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses