For the following three vectors, what is 3C·(2A x B )?

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The discussion revolves around calculating the expression 3C·(2A x B) using the provided vectors A, B, and C. The user initially computes 2A x B and arrives at the result 66i - 46j - 6k. However, they express confusion over the final calculation, as their app indicates an incorrect answer. Participants suggest re-evaluating the k component of 2A x B and emphasize the importance of attention to detail in such calculations. The user acknowledges their struggle with the assignment and seeks clarification on their approach.
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For the following three vectors, what is 3C·(2A x B )?

A = 2.00i + 3.00j - 9.00k
B = -3.00i + 3.00j + 2.00k
C = 5.00i - 8.00j


2AxB=(12+54)+(8-54)+(12-18)

2AxB=66i - 46j -6k

3C·(2AxB)= (66x15)i + (-46x-24)j = 2094

the app is telling me it's incorrect. I don't know what I'm doing wrong! thanks in adv
 
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Check your k component of 2AxB
 
looks like i was in the write spot sorry. checking...
 
isn't k irrelavtant considering Cz is zero
 
correction "right spot". I've been workin on this asssignment all day. I'm losing my attention to detail. Probably why I'm having trouble. lol
 
noeinstein said:
correction "right spot". I've been workin on this asssignment all day. I'm losing my attention to detail. Probably why I'm having trouble. lol

Check this thread: https://www.physicsforums.com/showthread.php?t=185106

and please do not multiply-post a problem in the future!
 
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