- #1
Physics697
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Actually I have two questions
Vectors A and B are shown on the figure below. Which one of the
following statements is correct?
a) A . B = 0 and A × B ≠ 0
b) A . B ≠ 0 and A × B = 0
c) A . B ≠ 0 and A × B ≠ 0
d) A . B = 0 and A × B = 0
Picture: http://i.imgur.com/X0GB9.png
A.B = AxBx + AyBy
Obviously, the answer is zero. but the problem is the difference between A . B and A x B. I have long thought that those two are the same, but this question confused me.
I tried google for a bit and found out that [ dot product (u . v) gives a scalar ] and [ cross product (u x v) gives a pseudovector ]. It's my first time hearing about a pseudovector =_=
My second question is also about Vectors Multiplication
A and B are the two vectors shown in the figure. Vector A is along the positive x
axis and has a magnitude of 5 cm, and the vector B is in the x-y plane at an angle 30º
with the positive x-axis and has a magnitude of 4 cm. A × B =
a) 20 cm2 in the +x direction b) 10 cm2 in the +y direction
c) 10 cm2 in the +z direction d) 20 cm2 in the -y direction
A.B = AxBx + AyBy
When I tried to solve it I got C= 17.5 + 0, so the answer might be a.
This cm^2 and the +z confused me, so I just wanted to confirm.
Homework Statement
Vectors A and B are shown on the figure below. Which one of the
following statements is correct?
a) A . B = 0 and A × B ≠ 0
b) A . B ≠ 0 and A × B = 0
c) A . B ≠ 0 and A × B ≠ 0
d) A . B = 0 and A × B = 0
Picture: http://i.imgur.com/X0GB9.png
Homework Equations
A.B = AxBx + AyBy
The Attempt at a Solution
Obviously, the answer is zero. but the problem is the difference between A . B and A x B. I have long thought that those two are the same, but this question confused me.
I tried google for a bit and found out that [ dot product (u . v) gives a scalar ] and [ cross product (u x v) gives a pseudovector ]. It's my first time hearing about a pseudovector =_=
My second question is also about Vectors Multiplication
Homework Statement
A and B are the two vectors shown in the figure. Vector A is along the positive x
axis and has a magnitude of 5 cm, and the vector B is in the x-y plane at an angle 30º
with the positive x-axis and has a magnitude of 4 cm. A × B =
a) 20 cm2 in the +x direction b) 10 cm2 in the +y direction
c) 10 cm2 in the +z direction d) 20 cm2 in the -y direction
Homework Equations
A.B = AxBx + AyBy
The Attempt at a Solution
When I tried to solve it I got C= 17.5 + 0, so the answer might be a.
This cm^2 and the +z confused me, so I just wanted to confirm.