Would one be pushing as much as their weight?

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Homework Help Overview

The discussion revolves around the mechanics of pushing weight, specifically comparing the work done in a chest press machine to lifting one's body weight in a chair lift scenario. Participants explore the relationship between force, distance, and work in these contexts.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Some participants examine the equivalence of work done in different scenarios, questioning how the ratio of distances affects the weight being pushed. Others inquire about the implications of mechanical advantage in this context.

Discussion Status

Participants are actively engaging with the concepts of work and mechanical advantage, with some offering insights into the relationship between force and distance. There is a productive exploration of how these principles apply to the original poster's question, though no consensus has been reached.

Contextual Notes

There is a noted uncertainty regarding the specific ratio of distances in the scenarios discussed, which may influence the understanding of work done versus weight pushed. The original poster also expresses a desire for clarification on these concepts.

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Homework Statement
In the following video, there is a machine. https://youtu.be/a_CGlAnxO5c It looks like a chest press machine but doesn't have weights attached - only attached to the chair. Would one be lifting as much as they weigh?
Relevant Equations
I was thinking it might have something to do with W = F•d
Because one is effectively pushing in the same way as a chest press machine, wouldn't the work done be the same?

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Welcome to PF.

Yes, it does look like how you describe it. The only caveat would be the ratio between the chest press distance and the chair lift distance. I couldn't tell if it was 1:1 or maybe more like 2:1. The work will still be the same, but you would only be pressing half of your weight in the latter case.
 
berkeman said:
Welcome to PF.

Yes, it does look like how you describe it. The only caveat would be the ratio between the chest press distance and the chair lift distance. I couldn't tell if it was 1:1 or maybe more like 2:1. The work will still be the same, but you would only be pressing half of your weight in the latter case.

Hello! Thank you for the warm welcome!
If it is not too much trouble, may I ask how the ratio would change the weight but not the work? I imagined it as a pulley system so the weight would be the same but the work done would change because of differing distances? Is this an incorrect way to look at it?
 
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