What is the Force Exerted by a Spring in a Moving Elevator?

  • Thread starter Thread starter mrshappy0
  • Start date Start date
  • Tags Tags
    Elevator Spring
Click For Summary

Homework Help Overview

The problem involves three masses suspended from identical springs in an elevator that is moving downward but accelerating upward. The inquiry focuses on determining the force exerted by the bottom spring on the bottom mass, considering the dynamics of the system under these conditions.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the implications of the spring constant k, questioning whether it remains constant when the elevator is in motion. There is also mention of the importance of drawing a Free-Body Diagram to analyze the forces acting on the masses.

Discussion Status

The discussion is ongoing, with participants expressing confusion about the relationship between the elevator's motion and the spring constant. Some guidance has been offered regarding the use of Free-Body Diagrams, but there is no explicit consensus on the approach to take.

Contextual Notes

There is a noted ambiguity in the description of the elevator's state, as it is referred to as both motionless and moving, which may affect participants' understanding of the problem setup.

mrshappy0
Messages
97
Reaction score
0

Homework Statement



Three masses m1 = 3.1 kg, m2 = 9.3 kg and m3 = 6.2 kg hang from three identical springs in a motionless elevator. the elevator is moving downward with a velocity of v = -2.3 m/s but accelerating upward with an acceleration of a = 4.8 m/s2. (Note: an upward acceleration when the elevator is moving down means the elevator is slowing down.) What is the force the bottom spring exerts on the bottom mass?

Homework Equations



f=-kx

The Attempt at a Solution



Some of my confusion lies with k. Since k is a constant is it the same value as if the elevator was motionless or does k change when the elevator moves?
 
Physics news on Phys.org
mrshappy0 said:
Some of my confusion lies with k. Since k is a constant is it the same value as if the elevator was motionless or does k change when the elevator moves?
The spring constant k is constant in the elastic region of the spring. Assume this for your solution.
 
Still not sure how to solve this I guess
 
Draw your Free-Body Diagram first.
 
How is it this possible "... a motionless elevator. the elevator is moving " ?

Follow flyingpig's advice !
 
SammyS said:
How is it this possible "... a motionless elevator. the elevator is moving " ?

Follow flyingpig's advice !

I think he means the masses are motionless wrt the lift and not bouncing around - but yes free body diagram.
 

Similar threads

Calculating Net Force of 3 Blocks in an Elevator
  • · Replies 9 ·
Replies
9
Views
2K
How do you know when k in Hooke's law is positive or negativ
  • · Replies 2 ·
Replies
2
Views
3K
Three masses in an elevator accelerating downwards
  • · Replies 8 ·
Replies
8
Views
3K
Work / Energy Elevator / Spring Problem
  • · Replies 5 ·
Replies
5
Views
5K
Forces and Elevators: Free-Body Diagrams and Calculations
  • · Replies 9 ·
Replies
9
Views
7K
Distribution of Energy when work is done on a system of 2 masses connected by a spring
  • · Replies 17 ·
Replies
17
Views
2K
Action-Reaction Forces on an Elevator
  • · Replies 5 ·
Replies
5
Views
3K
Oscillating Spring Block System inside elevator
  • · Replies 8 ·
Replies
8
Views
5K
What am I doing wrong in my calculations
  • · Replies 7 ·
Replies
7
Views
13K
Forces acting on a box-pulley system in an elevator?
  • · Replies 33 ·
2
Replies
33
Views
8K