Question

Find u * v, if u= 12j and v = i + 5j a (1,60) b (0,60) c -60 d 60

Answer 1

The correct answer for this problem would have to be D hope this helps:)

Answer 2

Answer:  The correct option is (d) 60.

Step-by-step explanation:  We are given to find u * v, if the vectors u and v are defined as follows :

$u=12j,~~~v=i+5j.$

We know that

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

So, we have

$u*v\\\\=(12j)*(i+5j)\\\\=12j.i+12j.5j\\\\=12\times 0+60\times 1\\\\=0+60\\\\=60.$

Thus, the value of u * v is 60.

Option (d) is CORRECT.