Resultant of vertical forces
$R = \Sigma F_V$
$R = 60 + 20 - 30$
$R = 50 \, \text{ kN downward}$
Moment about point A
$M_A = 60(4) - 20(1)$
$M_A = 220 \, \text {kN}\cdot\text{m clockwise}$
Location of R as measured from point A
$Rd = M_A$
$50d = 220$
$d = 4.4 \, \text{ m}$
Magnitude of horizontal couple at B and C
$2F = M_A$
$2F = 220$
$F = 110 \, \text{ kN}$
Thus the given system is equivalent to downward force of 50 kN at point A and clockwise couple of 220 kN·m. The couple is represented by 110 kN horizontal forces at B and C. The force at B is to the right and the force at C is to the left, producing the clockwise couple. answer
