Reaction forces are given in the figure below for beam ABCDE. The bending moment at C (in kN ∙ m) is:
A) 0.84 kN ∙ m
B) 0.96 kN ∙ m
C) 1.04 kN ∙ m
D) 1.36 kN ∙ m

Question

Reaction forces are given in the figure below for beam ABCDE. The bending moment at C (in kN ∙ m) is: 
A) 0.84 kN ∙ m 
B) 0.96 kN ∙ m 
C) 1.04 kN ∙ m 
D) 1.36 kN ∙ m

Quizplus · Accepted Answer

Taking moments about point C, we get
-RA x 2 - 8kN x 4 - 16kN x 6 + 8kN x 8 + RB x 10 = 0
Solving for RB, we get RB = 2.4 kN
Taking moments about point D, we get
-RA x 4 - 8kN x 2 - 16kN x 4 + MC - 2.4 kN x 6 = 0
Solving for MC, we get MC = 1.04 kN ∙ m, which is the bending moment at point C.

Reaction Forces Are Given in the Figure Below for Beam