Question

Determine the moment of each of the three forces about point A.

Fi 250 N 30 2 300 N 60° 4 m F 500 N

Answer 1

Moment due to Force F₁ about A

Moment = Perpendicular Force* distance from A

$M_{1} =F_{1}cos30 *2m+F_{1}sin30*0m$

$M_{1} =250Ncos30 *2m+0$

ANSWER: $M_{1} =433Nm$ clockwise

==============================

Moment due to Force F₂ about A

Moment = Perpendicular Force* distance from A

$M_{2} =F_{2}sin60*(2m+3m)+F_{2}cos60*0m$

$M_{2} =300N*sin60*5m+0$

ANSWER: $M_{2} =1299Nm$ clockwise

============================

Moment due to Force F₃ about A

Moment = Perpendicular Force* distance from A

$M_{3} =F_{3}cos\theta *(2m+3m)+F_{3}sin\theta (4m)$

$M_{3} =500N*4/5*(5m)-500N*3/5*(4m)$

$M_{3} =2000-1200$

ANSWER: $M_{3} =800Nm$ clockwise

=======================