Item 6 Part A The two trees in the figure are 7.0 m apart. A back- packer is try

Question

Item 6 Part A The two trees in the figure are 7.0 m apart. A back- packer is trying to lift his pack out of the reach of bears. Figure 1) Calculate the magnitude of the force F that he must exert downward to hold a 17-kg backpack so that the rope sags at its midpoint by 1.3 m Ignore the friction between the rope and the branch on the left. Express your answer using two significant figures. F 224 Submit My Answers Give Up Figure 1 of 1 Incorrect; Try Again; 4 attempts remaining Save Part B Calculate the magnitude of the force F that he must exert downward to hold a 17-kg backpack so that the rope sags at its midpoint by 0.17 m Express your answer using two significant figures. F 1700 N Submit My Answers Give Up

Explanation / Answer

a) theta = tan-1 [y / (L/2)] = tan-1 [1.3 / (7.0/2)]

theta = 20.38 deg

sigma Fy = 0

2 F sin theta - m g = 0

F = m g / 2 sin theta = (17 * 9.8) / (2 * sin 20.38)

magnitude of forece = 239.2 N

b) theta = tan-1 [y / (L/2)] = tan-1 [0.17 / (7.0/2)] = 2.78 deg

2 F sin theta - m g = 0

F = m g / 2 sin theta = (17 * 9.8) / (2 * sin 2.78)

= 1700 N

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

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