Question

Three vectors of magnitudes respectively, 1 unit,
2 units and 3 units are directed along the three
sides of an equilateral triangle. Then the resultant
of the three vectors is of -
(A) 1 unit
(B) 2 unit
(C) 13 units (D) 14 units​

Answer 1

Answer:

In this  case I am assuming the side of 3 unit to be the base directed along x- axis = 3i

The remaining two are inclined to the base at an angle of 60

I am assuming 1 unit to be inclined along positive x axis therefore

1= i÷2 + √3j÷2

Similarly for 2 units it is in opposite direction

2=-i +√3j

Adding all the three vectors , the resultant becomes 5i÷2 +3√3j ÷2

resultant =  √ (25+27)÷4= √13  is the right answer