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Let vecu= hati + hatj , vecv = hati -hat...

Let `vecu= hati + hatj , vecv = hati -hatj and vecw =hati + 2hatj + 3 hatk` If ` hatn` isa unit vector such that `vecu .hatn=0 and vecv .hatn =0 , " then " |vecw.hatn|` is equal to

A

3

B

0

C

1

D

2

Text Solution

Verified by Experts

The correct Answer is:
A
we have,
` vecu.hatn and vecv.hatn=0`
` hatn bot vecu and hatn bot vecv Rightarrow hatn = +- (vecu xx vecv)/(|vecu xx vecv|)`
Now, ` vecu xx vecv = (hati + hatj ) xx ( hati -hatj) = -2 hatk`
` hatn = +- hatk`
Hence ` |vecw hatn| = |(hati +2hatj =3hatk). ( +- hatk) =3`
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