Question

Three forces F1=3 i* +6j*, F2= 3i*+2j*, and F3 = -6i* + b j* are in equilibrium then the value of b=...... A. 8
B. -8
C. 6
D. -6

Answer 1

$\fontsize{18}{10}{\textup{\textbf{The value of b is 8}}}$

Explanation:

Since it is given that the three forces are in equilibrium, the sum of the i components and the j components individually must be zero.

It is apparent from the given vectors that sum of i components

3+3-6=0

Similarly the sum of y components

6+2+b=0

b=-8

So the value of b is 8