Question

The unit vector in the direction of the resultant of P = 2i +i – 3k and Q = i + 3j – 9kis (A) 3i+4j-2k 13 (B) 3i+4j-12k 13 (C) -3i+4j+12k 13 (D) -31–4j+12k /13​

Answer 1

Answer:

Resultant = 5i + 4j – 12k

| Resultant | = ( 5² + 4² + 12² )½ = (185)½

Unit vector = Resultant / | Resultant |

= ( 5i + 4j –12k ) / ( 185 )½

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