Chapter 09, Problem 75 The figure shows an outstretched arm (0.61 m in length) t

Question

Chapter 09, Problem 75 The figure shows an outstretched arm (0.61 m in length) that is parallel to the floor. The arm is pulling downward against the ring attached to the pulley system, in order to hold the 98-N weight stationary. Topull the arm downward, the atssmus dorsi muscle apples the ce in the figure at,pont that is .OS9 m on the shoulder int and one ted at an angleof29 Temonweg" , and a center of gravity (cg) that is located 0.28 m from the shouilder joint. Find the magnitude of M 0.61 m

Explanation / Answer

The free body diagram for the problem is as below -  

.|?-----------(0.61)m-----------?|98N
.|?-------(.28)m-----?|...........?
.|?--(.069)m---?|.....|(54)N...|
o===========?==v=====|
R............(.29º ? B
.................. ? .
............... ?
............ ? D .
......... ?
.... ? .M

From ?RDB we have -

sin 29º = (RD) / (0.069)
RD = sin 29º (0.069)

RD = (0.484)(0.069) = 0.033 m

Now, taking summation of moments about Point R = 0

? M® = 0.......(+???-)

=> 0 = M(RD) + 54N(0.28) - 98N (0.61)
=> M(RD) = 98(0.61) - 54(0.28)
=> M(0.033) = (59.78 - 15.12) = 44.66

=> M = 44.66 / 0.033 = 1353.3 N

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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