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

In summary, three masses with values of 3.1 kg, 9.3 kg, and 6.2 kg are suspended from identical springs in a motionless elevator. The elevator is then observed to be moving downwards with a velocity of -2.3 m/s but accelerating upwards with a constant acceleration of 4.8 m/s2. The question asks for the force exerted by the bottom spring on the bottom mass. The equation f=-kx is relevant to this problem, with the spring constant k remaining constant in the elastic region. A free-body diagram should be drawn in order to solve this problem.
  • #1
mrshappy0
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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?
 
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  • #2
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.
 
  • #3
Still not sure how to solve this I guess
 
  • #4
Draw your Free-Body Diagram first.
 
  • #5
How is it this possible "... a motionless elevator. the elevator is moving " ?

Follow flyingpig's advice !
 
  • #6
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.
 

1. What is the effect of gravity on a spring in a moving elevator?

The effect of gravity on a spring in a moving elevator depends on the direction of the elevator's movement. If the elevator is accelerating upwards, the spring will experience a greater force of gravity, causing it to stretch. If the elevator is accelerating downwards, the spring will experience a lesser force of gravity, causing it to compress.

2. How does the spring behave in a stationary elevator compared to a moving elevator?

In a stationary elevator, the spring will remain at its natural length. However, in a moving elevator, the spring will either stretch or compress depending on the direction of the elevator's movement.

3. Does the mass of the spring affect its behavior in a moving elevator?

The mass of the spring does not affect its behavior in a moving elevator. The behavior of the spring is determined by the direction and magnitude of the force of gravity acting on it.

4. How does the speed of the elevator affect the behavior of the spring?

The speed of the elevator does not directly affect the behavior of the spring. The behavior of the spring is determined by the direction and magnitude of the force of gravity acting on it, which is affected by the acceleration of the elevator.

5. Can the spring break or weaken due to the movements of the elevator?

The spring may experience wear and tear over time due to the repeated stretching and compressing in a moving elevator. However, as long as the spring is made of a durable material, it should not break or weaken significantly.

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