Answer:
Explanation:
Assume the rod is horizontal
Sum vertical forces to zero
F - 8 - 4 - 2 - 3 = 0
F = 17 N
While this result answers precisely the question asked, it is not sufficient to guarantee equilibrium. We must also locate this force by summing moments to zero. Let's choose to sum about the left end.
8[9/2] + 4[1] + 2[6] + 3[4] - 17[x] = 0
x = 3.76470588...
the force must be supplied upward approximately 3.765 m from the left end
The rod does not actually have to be horizontal. Moment arms will all be proportionately reduced by tilting the bar from horizontal and the results will be identical. Assuming horizontal just reduces the calculation effort.