Does getting sucked up require more energy then getting pushed away?

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Discussion Overview

The discussion revolves around the energy requirements for an object being "sucked up" versus being "pushed away," with considerations of mass, force, and efficiency. Participants explore theoretical scenarios and practical implications, including the role of gravitational potential energy and efficiency of devices.

Discussion Character

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

Main Points Raised

  • Some participants propose that the energy required depends on the efficiency of the device performing the action, suggesting that if perfectly efficient, there would be no difference in energy required.
  • Others argue that pushing away in a horizontal direction does not change gravitational potential energy, while sucking up vertically does, necessitating additional energy to overcome gravitational potential energy.
  • A participant suggests testing the scenario with an idealized adiabatic piston and an ideal gas to compare work done in compressing and expanding.
  • One participant notes that the context of the question is unclear and suggests that a sketch of the arrangement could clarify the discussion.
  • Another participant mentions that in open conditions, directing a jet can create a higher pressure, affecting the efficiency of "sucking" compared to "pushing."
  • Newton's third law is referenced, indicating that the question may not be complete or fully framed.

Areas of Agreement / Disagreement

Participants express differing views on the energy requirements for sucking versus pushing, with no consensus reached on the overall question. Some points of agreement exist regarding the role of efficiency and gravitational potential energy, but the discussion remains unresolved.

Contextual Notes

Participants note the importance of clarifying the context and specific scenarios being discussed, as assumptions about the arrangement and conditions may significantly influence the energy considerations.

Do0msDay
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For instance The object has same mass in both cases.
And the force of getting sucked and pushed away is also the same.

Does getting sucked up require more energy then getting pushed away?
 
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Do0msDay said:
For instance The object has same mass in both cases.
And the force of getting sucked and pushed away is also the same.

Does getting sucked up require more energy then getting pushed away?

Why don't you test this with an idealized adiabatic piston and an ideal gas trapped inside the piston? Is the work done in compressing the piston by an amount equal or different than the work done by the gas in expanding back to the piston's original position?

Zz.
 
ZapperZ said:
Why don't you test this with an idealized adiabatic piston and an ideal gas trapped inside the piston? Is the work done in compressing the piston by an amount equal or different than the work done by the gas in expanding back to the piston's original position?

Zz.

I don't have one.
 
Do0msDay said:
I don't have one.

No one has an "idealized piston". It wasn't meant to be an experiment. It was meant for you to calculate!

Zz.
 
Do0msDay said:
For instance The object has same mass in both cases.
And the force of getting sucked and pushed away is also the same.

Does getting sucked up require more energy then getting pushed away?

The required energy will depend on the efficiency of the device doing the sucking/pulling; if they were perfectly efficient there would be no difference. In practical applications pushing is often more efficient, but this is by no means universally true.
 
No one has asked you the actual context of this question. A sketch of the sort of arrangement you are considering would help. I have a feeling you may not be talking in terms of pistons and cylinders.
 
Do0msDay said:
For instance The object has same mass in both cases.
And the force of getting sucked and pushed away is also the same.

Does getting sucked up require more energy then getting pushed away?

If "sucking up" you mean in the vertical direction upwards; and by being pushing away you could mean in any direction; then there would be a difference.

By going upwards, the mass will have an increase in gravitational potential energy. You will have to supply this energy.
By pushing away, say in the horizontal direction, the gravitational potential energy stays the same. If on a surface, friction due to sliding will require an energy expenditure.

Pushing away in any other direction from the horizontal entails a change in potential energy. This could help you in if the final position is below the initial, or add to the energy expenditure if above the initial position.

You may have to clarify your question.
 
One thing that's certain, in open conditions, is that 'blow' can be directed from a jet, producing a higher pressure in a given direction. If you have a low pressure in an orifice, air will flow in from all directions and you can't 'focus the suck' as much because, for a given total amount of air flow, the pressure gradient is less.
 
NEWTON's third LAW can work here.
Besides, Question is not complete.
 

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