- #1
Elysian
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Homework Statement
1) Two men are near a hole, One man walks 12m east and then 12m North from a hole, the other walks 15m west and then 11m north, Find the dot product of their net displacements from the tree
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2) Vector A = -i +2j - 5k, Vector B = 3i +2j -2k
Find the magnitude and direction of the vector difference A -B
Homework Equations
|A||B|cos(t) = A(x)B(x) + A(y)B(y) = |A||B|
The Attempt at a Solution
1 )I didn't calculate the resultant as I think you don't need it, I used the components given
A = 12i + 12j
B = -15i +11j
|A||B| = (12*-15) + (12*11) = -48.
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2) A - B = -4i -3k
|A-B| = [itex]\sqrt{-4^2 + 0^2 + -3^2}[/itex] = 5.0
arctan([itex]\frac{0}{-4}[/itex] = 0
So the magnitude is 5.0 and the angle is 0 degrees? This seems wrong to me..
If anyone can tell me if I did these right or give me a tip in the right direction, it'd be very much appreciated. Thanks in advance