Move a mass on frictionless surface in a vacuum chamber

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Discussion Overview

The discussion revolves around the energy required to move a mass horizontally on a frictionless surface within a vacuum chamber. Participants explore the implications of initial conditions, forces applied, and the relationship between mass and energy in this context.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions how much energy is necessary to move one kilogram of mass horizontally for one meter, assuming it starts from rest.
  • Another participant suggests that the energy required depends on the time taken to move the mass, noting that more energy results in greater acceleration and less time to cover the distance.
  • Concerns are raised about whether a very small force applied briefly can initiate movement of the mass from rest in a frictionless environment.
  • A participant asks about the net force on the object and references Newton's laws to understand the motion after applying a small force.
  • There is a question regarding whether the mass of an object affects the energy needed to move it one meter in a specified time, particularly when comparing objects of different weights but the same volume and shape.
  • Another participant emphasizes the need to consider the speed of the object at the one-meter mark and its relationship to kinetic energy when discussing energy requirements.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between force, mass, and energy requirements, indicating that multiple competing perspectives remain without a consensus on the specific energy needed to initiate movement or the effect of mass on energy requirements.

Contextual Notes

Participants have not reached a resolution on the minimum energy required to move the mass or the implications of mass on energy needs, leaving several assumptions and conditions unresolved.

Dante Meira
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How much energy is necessary to move one kilogram of mass horizontally for one meter on a perfectly frictionless surface inside a vacuum chamber?

Assuming the initial velocity of the mass is zero, the mass is at rest.
 
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Dante Meira said:
How much energy is necessary to move one kilogram of mass horizontally for one meter on a perfectly frictionless surface inside a vacuum chamber?

Assuming the initial velocity of the mass is zero, the mass is at rest.
What are your thoughts on this?
 
Chestermiller said:
What are your thoughts on this?

I guess the energy needed will depend on the time you want the mass to take to move that one meter. If you use little energy, the one kilogram mass will accelerate less and will take more time to move one meter. The more energy you use, more the one kilogram mass will accelerate, and it will take less time to move one meter horizontally.

But I wonder if there is a minimal bound in how much energy is needed to make the one kilogram mass start to move from rest on an frictionless horizontal surface in a chamber with no air resistance.

If you apply a very small force (microNewtons) for just a very brief moment (microsseconds) will that be enough to move the one kilogram mass from rest? Will it start to move horizontally in a frictionless environment, even if in a very slow speed?
 
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Dante Meira said:
If you apply a very small force (microNewtons) for just a very brief moment (microsseconds) will that be enough to move the one kilogram mass from rest? Will it start to move?
What is the net force on the object? What does Newton's second law say about this situation?

After you're done applying this small force for a short time... what does Newton's first law say about the motion of the object?
 
The object is at rest and the only force applied is this small force for a small amount of time, in a direction parallel to the ground.

What I really want to know is: in this case, will the mass of the object have any effect on the energy necessary to move the object one meter in a given period of time?

For example: in the same vacuum chamber with no air resistance and with perfectly frictionless surface, we put two objects of the same volume and shape, but with different densities, so one of them weights one kilogram, and the other weights 20 kilograms. Considering no friction at all (not even from air) and horizontal movement (in relation to gravity, that is: not "against" gravity and not in the direction of gravity, but neutral), and supposing we want to move the two objects one meter in 10 seconds, will it be necessary to use more energy to move the 20 kg object than the 1 kg object?

That's my doubt.
 
Dante Meira said:
The object is at rest and the only force applied is this small force for a small amount of time, in a direction parallel to the ground.

What I really want to know is: in this case, will the mass of the object have any effect on the energy necessary to move the object one meter in a given period of time?
What is the smallest number greater than zero?
 
Dante Meira said:
What I really want to know is: in this case, will the mass of the object have any effect on the energy necessary to move the object one meter in a given period of time?
That is a different question than you asked in your first post. To answer this one you'll want to consider the speed of the object as it passes the one meter point, and what that says about its kinetic energy.
 

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