0:00 / 0:00
  • Specifies the direction of a vector (like standing at the tail and point to the tip)
  • Points in the direction of the vector & “gives direction” (to make it a vector)
  • “unit-less”
  • magnitude of 1
  • the unit vector = (any vector / magnitude of that vector)



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In the figure below, you can see the unit vector U pointing to the tip of vector V


EX: Given vector A as (4i+2J+4k)m. Build the unit vector for A.




vectorA = A uA

the magnitude of A = Ax2 + Ay2 + Az2\sqrt{Ax^{2}\ +\ Ay^{2}\ +\ Az^{2}} = 6

therefore, uA = vectorA / magA = 0.67i+0.33j+0.67k


(0.67i+0.33j+0.66k)
Find a vector whose length is one, that points in the same direction as the vector u=<2,1,2>\vu = \rowvecth{2}{1}{-2}

Practice Question: Unit Vector

Which one of the following is not a unit vector?
checklist
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  1. Grab a piece of paper and try this problem yourself.
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EX: Given vector B as (3i-2J+8k)m. Build the unit vector for B.