Bridge in the Context of A Spring.

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The discussion centers on a physics problem involving tourists jumping on a poorly-designed bridge. The key question is whether the tourists are in equilibrium while their feet are still in contact with the bridge. It is clarified that they are indeed in equilibrium because they are not moving, maintaining a constant velocity of zero. The terminology of "static equilibrium" is introduced to articulate their state more clearly. Overall, the reasoning presented aligns with the principles of physics regarding equilibrium during the jump.
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We have weekly problem sets that lead us through a "story" of sorts. In this week's, a group of tourists are on a newly-built, albeit poorly-designed bridge. The question reads:

"The tourists bend their knees and, at the count of three, jump upward simultaneously. While their feet are in contact with the bridge, as they straighten out their legs during their jump, are the tourists in equilibrium? Why or why not?"

I know that equilibrium means to have a constant velocity. I was thinking that they WERE in equilibrium because even though they're accelerating upward (?), they're not moving and therefore their velocity is constant at zero until their feet leave the bridge. Does this make sense? Is that appropriate physics 'language'? It seems that I'm missing some key terminology or something that would make it sound more articulate.

Thanks!
Laura.
 
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Yes, your reasoning is correct. The tourists are in equilibrium while their feet are in contact with the bridge, since they are not moving. You could say that the tourists are at rest and maintain a state of static equilibrium as they jump.
 
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