A uniform beam of length x = 1.0m and mass 10kg is attached to a wall by a cable

Question

A uniform beam of length x = 1.0m and mass 10kg is attached to a wall by a cable at angle ?=30 ? to the horizontal, as shown in the figure. The beam is free to pivot at the point where it attaches to the wall.

Part A

What is the tension in the cable?

Express your answer using two significant figures.

A uniform beam of length x = 1.0m and mass 10kg is attached to a wall by a cable at angle ?=30 ? to the horizontal, as shown in the figure. The beam is free to pivot at the point where it attaches to the wall. Part A What is the tension in the cable? Express your answer using two significant figures.

Explanation / Answer

Take the moments about the point of wall attachment. The Center-of-Gravity (CG) of the beam is at 0.5m, and the weight of the beam is m*g = 10*9.8 = 98 N. Only the vertical component of the cable tension contributes to the moment calculation, since the horizontal component has a zero radius or "moment arm" relative to the wall point of attachment. Let "T" be the tension in the cable, and then the vertical component of the cable tension is:

F_v = T*Sin(30)

Equating the two moments:

0.5*m*g = 1.0*T*Sin(30)

.5*98/Sin(30) = T = 98N

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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