ENGINEERING MECHANICS - STATICS AND DYNAMICS (12TH EDITION): PART 2

M RO =Σ M O ; M RO = F 1 cos ( ) θ 2 e − F 1 sin ( ) θ 2 f − F 2 cos ( ) θ 1 b 2 − a 2 − F 2 sin ( ) θ 1 a M RO = − 858 lb in ⋅ M RO = 858 lb in ⋅
Problem 4-5
Determine the magnitude and directional sense of the resultant moment of the forces at[r]

Problem 5-43
The upper portion of the crane boom consists of the jib AB, which is supported by the pin at A,
the guy line BC, and the backstay CD, each cable being separately attached to the mast at C. If
the load F is supported by the hoist line, which passes over the pulley at B, de[r]

The aircraft-hangar door opens and closes slowly by means of a motor which draws in the cable AB. If the door is made in two sections (bifold) and each section has a uniform weight
W and length L , determine the force in the cable as a function of the door's position θ[r]

= k y = 59.4 mm
Problem 10-29
Determine the moment of inertia for the beam's cross-sectional area with respect to the x' centroidal axis. Neglect the size of all the rivet heads, R , for the calculation. Handbook values for the area, moment of inertia, and location of the centroid C[r]

Now find the magnitude of the resultant force.
F R = F 1v + F 2v + F 3v F R = 462.9 lb
Problem 2-51
Determine the magnitude of force F so that the resultant F R of the three forces is as small as possible. What is the minimum magnitude of F R ?

Problem 8-36
In an effort to move the two crates, each of weight W , which are stacked on top of one another, the man pushes horizontally on them at the bottom of crate A as shown. Determine the smallest force P that must be applied in order to cause impending motion. Explain what happens.[r]

The three concurrent forces acting on the post produce a resultant force F R = 0. If F 2 = (1/2)F 1 , and F 1 is to be 90° from F 2 as shown, determine the required magnitude F 3 expressed in terms of F 1 and the angle θ .
Solution: Use the primed coordiate[r]

d
= I y = 1.41 m 4
Problem 10-25
The polar moment of inertia for the area is I C about the z axis passing through the centroid C . The moment of inertia about the x axis is I x and the moment of inertia about the y' axis is I y' . Determine the area A .

= θ p1 = 6.08 deg
θ p2 = θ p1 + 90 deg θ p2 = 96.08 deg
Problem 10-90
The right circular cone is formed by revolving the shaded area around the x axis. Determine the moment of inertia l x and express the result in terms of the total mass m of the cone. The cone has a constant density[r]

Determine the force P acting on the cord which is required to maintain equilibrium of the horizontal bar
CB of mass M . Hint: First show that the coordinates s A and s B are related to the constant vertical length l of the cord by the equation 5 s B − s A = L .
Given:

F. Beer, E. R. Johnston Jr., D. Mazurek, Vector of Mechanics for Engineers, Statics & Dynamics, McGraw-Hill, 2013
TRỌNG TAM
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VD 1: Một thanh mảnh đồng chất trọng lượng w có dạng nửa đường tròn bánh kính r. Thanh được liên kết với giá cố định bằng chốt bản lề t[r]

Problem 8-99
The uniform beam of weight W 1 is supported by the rope which is attached to the end of the beam, wraps over the rough peg, and is then connected to the block of weight W 2 . If the coefficient of static friction between the beam and the block, and betw[r]

Each member of the truss is uniform and has a mass density ρ. Remove the external loads F 1 and F 2 and determine the approximate force in each member due to the weight of the truss. State if the members are in tension or compression. Solve the problem by assuming the we[r]

Problem 8-86
The truck, which has mass m t , is to be lowered down the slope by a rope that is wrapped around a tree. If the wheels are free to roll and the man at A can resist a pull P, determine the minimum number of turns the rope should be wrapped around the tree to lower the tru[r]

Engineering Mechanics – Statics 5.45 Equilibrium of a Rigid Body
HCM City Univ. of Technology, Faculty of Mechanical Engineering Nguyen Tan Tien
Fundamental Problems
- F5.5 The 25𝑘𝑔 bar has a center of mass at 𝐺. If it is supported by a smooth[r]

The board can be adjusted vertically by tilting it up and sliding the smooth pin A along the vertical guide G. When placed horizontally, the bottom C then bears along the edge of the guide, where the coefficient of friction is μ s . Determine the largest dimension d which will suppo[r]

Problem 9-51
The three members of the frame each have weight density γ . Locate the position ( x c , y c ) of the center of gravity. Neglect the size of the pins at the joints and the thickness of the members. Also, calculate the reactions at the fixed support A .

U S E O F T H E I N S T R U C T O R ’ S M A N U A L
The problem solution portion of this manual has been prepared for the instructor who wishes to occasionally refer to the authors’ method of solution or who wishes to check the answer of his (her) solution with the re[r]

This method creates a MATLAB fi le which has a .MAT fi le extension in Windows. If you save a fi le this way, you can retrieve all the commands in it and work with it again just like you can when working with fi les in any other computer program.
Sometimes, especially when working on complic[r]

lb =
Problem 5-91
The shaft assembly is supported by two smooth journal bearings A and B and a short link DC. If a couple moment is applied to the shaft as shown, determine the components of force reaction at the bearings and the force in the link. The link lies in a plane p[r]