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Homework Help: Finding cross product of two vectors a,b

  1. Sep 28, 2010 #1
    1. The problem statement, all variables and given/known data
    A vector of magnitude 17 units and another vector of magnitude 7.4 units differ in directions by 27°. Find (a) the scalar product of the two vectors and (b) the magnitude of the vector product ×.

    2. Relevant equations

    Right-hand rule, a*b=abcos(theta), A x B= absin(theta)

    3. The attempt at a solution
    Dot product => a*b= (17)(7.4)(cos(27))= 112.089

    Just not quite sure on how to do the cross product. The right hand rule gives me a vector pointing straight up the z axis when sweeping into b but not sure what values to plug in to absin(theta) Thanks.
  2. jcsd
  3. Sep 28, 2010 #2
    Hm. It seems the answer is just 17(7.4)(sin(27). Not sure geometrically why this is the case though.
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