I ^. (j^ x k^) is equal to______________?
Correct answer: A. 1
- A. 1
- B. i^
- C. j^
- D. k^
Explanation
Using the unit-vector cross-product rule, j x k = i, and therefore i·(j x k) = i·i = 1. The dot product of a unit vector with itself is 1, not another unit vector. Students may choose b because j x k produces i, but the final dot product with i must still be performed.
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About Scalar Product
The scalar product of two vectors is A dot B equals AB cos theta, producing a scalar determined by their magnitudes and included angle. Applications include work done and projection of one vector on another, with perpendicular vectors giving zero and the scalar product distinguished from the vector product.
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