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The resultant of two vectors of magnitu...

The resultant of two vectors of magnitude 3 units 4 units is 1 unit. What is the value of their dot product. ?

A

`-12` units

B

`-7` units

C

`-1` units

D

0

Text Solution

Verified by Experts

The correct Answer is:
A
`1=(3)^(2)+(4)^(2)+2(3)(4)cos theta=24`
`=24cos theta`
`cos theta=-1`
`vecA.vecB=AB cos theta`
`vecA.vecB=(3)/(4)(-1)=-12` unit
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