Work, force and displacement directions

AI Thread Summary
The discussion revolves around a physics question involving force and displacement vectors, specifically F= 160N x - 40N y and s= 14m x + 11m y. The user finds it counterintuitive that the force has a negative y-component while the displacement is positive in the y-direction. Responses clarify that multiple forces could be at play or that the object may have initial momentum affecting its motion. The scalar product method yields a work result of 1800J, indicating that the scenario is physically plausible despite initial assumptions. Overall, the conversation emphasizes the importance of considering all forces and initial conditions in such physics problems.
SecretSnow
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Hi guys! I stumbled upon this truly weird question that seems counter intuitive to me. For the purpose of this question, I'll use x,y,z as unit vectors without the roof because I'm using my phone now..
If F= 160N x - 40N y and s= 14m x +11m y (as stated in the question) is this physically possible? I mean, the y-force is in the negative direction which I would take as downwards, and the displacement is actually positive, or upwards! Continuing this question, using scalar product method, I get 1800J as my answer. Thanks!
 
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There are several ways this situation could come about. For example there could be other forces acting that you aren't told about, or the object being acted on by F could have some initial velocity and thus momentum in the y-direction. Unless you're specifically told that the object starts from rest, you can't make the assumption.
 
gneill said:
There are several ways this situation could come about. For example there could be other forces acting that you aren't told about, or the object being acted on by F could have some initial velocity and thus momentum in the y-direction. Unless you're specifically told that the object starts from rest, you can't make the assumption.

Yes, you're right. The question didn't specify that this is the only force. Thanks bro!
 
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