Problem 12.36 - Copy A crane in a marble quarry is mounted on the rock walls of
ID: 1501378 • Letter: P
Question
Problem 12.36 - Copy A crane in a marble quarry is mounted on the rock walls of the quarry and is supporting a 1900 kg slab of marble as shown in the figure. The center of mass of the 700 kg boom is located one-third of the way from the pivot end of its 15-m length, as shown.
Part A Find the tension in the horizontal cable that supports the boom.
ANSWER: T = kN
Part B What is the direction of the force on the boom at the pivot end? The angle measured from horizonal is
ANSWER: What is the direction of the force on the boom at the pivot end?
1)The angle measured from horizonal is less than 50 degree
2)same as 50 digree
3)greater than 50 degree
CMExplanation / Answer
In equilibrium Net torque = 0
T*L*sin50 = mg*L/3*cos50 + M*g*L*cos50
L = 15 m
m = 700 kg
M = 1900 kg
T*sin50 = (700*9.81*cos50/3) + (1900*9.81*cos50)
T = 17.56 KN
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along horizantal
Fx - T = 0
Fx = T
along vertical
Fy - mg - Mg = 0
Fy = (M+m)*g
angle = tan^-1(Fy/Fx)
angle = 81.6
greater than 50