Calculating Kinetic Energy: Understanding the Equation and Common Errors

[m2009aquario]

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?

 

[SHISHKABOB]

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.

 

[fishspawned]

i'm getting the same answer as you

 

[m2009aquario]

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