The scalar product of two perpendicular vectors is
Correct answer: C. zero
- A. maximum
- B. equal to their magnitudes multiplied
- C. zero
- D. negative
Explanation
Cos 90 is zero, so the dot product vanishes whenever the vectors are at right angles, and this is the standard test for perpendicularity. It is also why no work is done by a force acting at right angles to the displacement, such as the centripetal force on a body in circular motion. The dot product is maximum when the vectors are parallel and negative when the angle exceeds 90 degrees.
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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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