Question

A 17.2 metre, simply supported beam has 3 point loads. They are 325 N, 1.4 kN, and 4.4 kN and are located 2.4 m, 5.9 m and 14.8 metres respectively from the left hand support. What are the reactions at the supports

Answer 1

Let A be the left support and B the right support.

Sum of vertical forces:
RA + RB = 325 + 1400 + 4400 = 6125 N

Take moments about A (positive clockwise):
RB·17.2 = 325·2.4 + 1400·5.9 + 4400·14.8 = 74160 N·m
RB = 74160 / 17.2 = 4311.63 N

Then
RA = 6125 − 4311.63 = 1813.37 N

So the support reactions are approximately:
RA = 1813 N (1.813 kN) and RB = 4312 N (4.312 kN).