What is the expression for the velocity of the Car in Vector

AI Thread Summary
The discussion centers on determining the correct expression for the velocity of a car in vector form. The initial attempt suggested a simple velocity vector of v = 63i + 0j + 0k, indicating motion in one direction, but this was deemed incorrect. Participants noted ambiguity in the problem regarding the required units and whether the question pertains to velocity or position. Clarification was sought on the meaning of ##r_i## in the context of the position vector. Ultimately, the conversation highlights the importance of understanding the problem's requirements and the correct application of vector notation.
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Homework Statement


upload_2019-2-10_20-45-49.png


Homework Equations


v = I + j + k
v = d/t

The Attempt at a Solution



I thought the answer was as simple as: v = 63i + 0j + 0k, since the car only has motion in one direction...
...but I got it wrong, so clearly I'm missing something here.
 

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The question is somewhat vague. I see two aspects that are unclear.
What units are to be used in the answer?
Does it want an expression for velocity or one for location?
 
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I think the problem wants the expression for the position vector too, that is ##\vec{r}=r_i\cdot i +0j+0k##. What is ##r_i## here?
 
Whoops. Sorry, I should've had this picture there too:

upload_2019-2-10_22-54-36.png
 

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it says using the speed v and the unit vectors i,j,k

maybe try ##v\cdot \vec{i} +0\cdot\vec{j}+0\cdot\vec{k}##
 
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Thanks. I knew it was something silly.
 
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