Question 4
Analyse each force acting on the rigid body and follow the step to solve for the unknowns.
Determine the reactions on the beam. A is a pin support and B is a
roller.
45 kN/m
30 kN/m
30 kN/m
!!! Remember, roller has 1 unknown ONLY,
normal to the surface.
In this problem, the roller is slanted at 60°,
therefore it can be resolve in the x \textendash{} direction
and y \textendash{} direction.
B $F_B$ cos 60° N Careful when resolving this force. Only 1
unknown must appear $F_B$
A
60°
810 kN \textendash{} m
$F_B$ sin 60° N
$F_B$
3.6 m
-3.6 m
$F_{By}$
B
$F_{Bx}$
60°
Never resolve it this
$F_B$
way. This is as if there
are two (2) unknowns
acting at point B.