A 20.0- m -long uniform beam weighing 570 N rests on walls A and B , as shown in

Question

A 20.0-m-long uniform beam weighing 570N rests on walls A and B, as shown in the figure (Figure 1) .

Find the forces that the walls A and B exert on the beam when the person is standing at a point 1.5m to the right of B.

Find the forces that the walls A and B exert on the beam when the person is standing 2.4m to the right of A.

Please show steps!

A 20.0-m-long uniform beam weighing 570N rests on walls A and B, as shown in the figure Find the forces that the walls A and B exert on the beam when the person is standing at a point 1.5m to the right of B. Find the forces that the walls A and B exert on the beam when the person is standing 2.4m to the right of A.

Explanation / Answer

equating the upward total to the downward total:
570 + 570 = R1 + R2
1140 = R1 + R2 ...(1)

Take moments about any point (I am using the left end of the beam), and equate the clockwise moments to the anticlockwise:
570 * 5 + 570 * 10 = 3R1 + 15R2
8550 = 3R1 + 15R2 ...(2)

Substitute for R2 from (1) in (2):
8550 = 3R1 + 15(1140 - R1)
8550 = 12R1
R1 = 712.5 N.

From (1):
R2 = 427.5 N.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.