How Do You Calculate the Y-Component of Velocity in a 2D Kinematics Problem?

AI Thread Summary
To calculate the y-component of velocity in the given 2D kinematics problem, the participant is struggling with unclear graphs that mislabel the velocity components. The correct approach typically involves reading the value of vy directly from the graph at t=4 seconds, but the provided graphs are confusing and poorly labeled. The participant suspects that the acceleration due to gravity may play a role but is unsure how to incorporate it. Previous attempts to calculate the y-component yielded incorrect results, leading to frustration. Clarification on the graph's accuracy and proper interpretation is needed to resolve the issue.
creechur
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Homework Statement


A particle starts from rest at (r0) = 9m j-hat and moves in the xy-plane with the velocity shown in the figure . The particle passes through a wire hoop located at (r1)=20m i-hat, then continues onward.

https://www.physicsforums.com/attachment.php?attachmentid=7841&stc=1&d=1159234661

The question I'm having trouble with is finding the y-component of velocity at t=4


Homework Equations



I think it's v = vi + ay delta t



The Attempt at a Solution



I got -40 (express to only one sig fig) and it was wrong, so I have no idea what to do


Someone please just point me in the direction to go, and not to an older thread
 
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The graphs are confusing. Both claim to be of vx as a function of time, but are clearly showing different functions. Can you explain more what the two graphs are supposed to be showing?
 
the first graph (positive V) is Vx the second one is vy
 
Okay.

If that graph is the only information we have about vy, your question is unanswerable. Normally you would just read the value of vy at t=4 seconds on the graph. But whoever made the graph has done it sloppily, all we have is the cryptic "4y" label for the velocity at 4 seconds. Plus they mislabelled vx for the graph that should be vy.

Are these graphs something your professor provided in a printout? I can't believe a textbook would have something like this, since they normally have editors and proofreaders to troubleshoot errors like this.
 
It actually an online site that we do our homework on, I found those graphs elsewhere. I know it has something to do with the acceleration of gravity, but I submitted the answer 40 and got counted wrong (i submitted both negative and positive
 
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