Calculating Kinetic Energy: Understanding the Equation and Common Errors

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Homework Help Overview

The discussion revolves around calculating the kinetic energy of a 3kg object with a given velocity vector. Participants are examining the application of the kinetic energy formula and the implications of significant figures in their calculations.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants are comparing their calculated kinetic energy values and questioning the potential rounding of answers in reference materials. There is a focus on understanding how significant figures affect the final result.

Discussion Status

Some participants have expressed similar results in their calculations, and there is a consensus that rounding may be a factor in the discrepancy between the original poster's answer and the book's answer. The discussion is ongoing with no definitive resolution yet.

Contextual Notes

Participants are considering the rules of significant figures in relation to the velocity vector provided, which may influence the accuracy of their kinetic energy calculations.

m2009aquario
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kinetic energy, help!?

A 3kg object has a velocity < 6i -1j > m/s. What is its kinetic energy at this moment? According to the book I'm using the ans is 60J but I get 55.5 J...What em I doing wrong?
 
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They probably just rounded their answer. If you use sig figs, there's only one sig fig in < 6i -1j >, so they rounded 55.5 to 60 to conserve sig figs.
 


i'm getting the same answer as you
 


Hey thanks guys, I was really going nuts here trying to figure it out, it only made sense that the answer was rounded.
 

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