Calculate output forces of machines

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Discussion Overview

The discussion revolves around calculating the output forces of machines, particularly focusing on the mechanics of bicycles and levers. Participants explore the relationship between input and output forces, torque balances, and the effects of acceleration on these calculations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that the output force of a bicycle is less than the expected value calculated from torque balance due to factors like angular acceleration.
  • Others argue that the torque balance should hold true, questioning the source of the discrepancy in output force calculations.
  • A participant presents a formula for calculating the output force of a wheel based on the masses involved and the applied force.
  • Concerns are raised about where the extra torque goes during acceleration and how it relates to Newton's second law.
  • Some participants express confusion about energy transfer in levers, specifically questioning how energy is transmitted when no load is present.
  • There is a discussion about whether work in equals work out in the context of levers, with some suggesting that energy losses occur.
  • Participants emphasize the need for clarity in descriptions and equations to fully understand the principles involved in calculating output forces.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the calculations of output forces. Multiple competing views remain regarding the effects of acceleration, energy transfer, and the validity of torque balance in different scenarios.

Contextual Notes

Participants note that assumptions about friction and other factors may affect the calculations, and there are unresolved questions about energy loss and the behavior of systems without loads.

Who May Find This Useful

This discussion may be useful for individuals interested in mechanical engineering, physics, and applied mathematics, particularly those exploring the dynamics of machines and energy transfer principles.

  • #31
Ok. I know that there is no difference between the friction force and the force the tire imparts to the ground and they equal and opposite. What I was saying is that Eout is not entirely Eout, because the wheel is part of the bike. I know that Iadθ is the energy that goes into rotating the wheel giving it rotational kinetic energy, but the wheel also gains translational kinetic energy from a portion of mαr^2dθ. I thought this portion was Mw/Mbike.
 
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  • #32
Does that make any sense?
 

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