What is the magnitude of the cross product vec{A} times vec{B}?
What is the magnitude of the cross product vec{C} times vec{D}?
3 Answers
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If a vector b makes an angle θ with vector a.
The magnitude of the cross product is :
|a X b| = |a|.|b|sinθ
In your examples
(a) |a| = 6 and |b| = 4 θ = 180° – 135° = 45°
|a X b| = 6 X 4 X sin(45°) = 24(1/√2) = 12√2 units (Multiplying top and bottom be √2)
(b) In this case vectors are anti parallel so θ = 180°
|c X d| = 0 since sin(180°) = 0.
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Magnitude Of Cross Product
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http://en.wikipedia.org/wiki/Cross_product#Definit…
simple problem. why not try and post back if you get stuck. you’ll be better off down the road if you at least try…
cheers