Question

ii) The magnitude of scalar product of the vectors Ā = 2j+5k and B = 3i+ 4k is
a 20
b) 22
c) 26
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Answer 1

Answer:

(a) 20

Explanation:

A=2j+5k

B=3i+4k

A.B=(2j+5k) (3i+4k)

=2j(3i+4k) +5k(3i+4k)

=6*i.j+8*j.k+15*k.i+20*k.k

= 6*0+8*0+15*0+20*1

i.j=j.k=k.i=0, k.k=1

A.B = 20