Concept explainers
Determine the moment about the origin O of the force F = 4i + 10j + 6k that acts at a point A. Assume that the position
(a)
The moment about origin
Answer to Problem 3.20P
The moment about origin
Explanation of Solution
Write an expression to calculate the moment of the force at the origin
Here
Write an expression to represent force vector.
Here,
Write an expression to represent position vector of point
Here,
Write an expression to calculate the moment of force.
Conclusion:
Substitute
Thus, the moment about origin
(b)
The moment about origin
Answer to Problem 3.20P
The moment about origin
Explanation of Solution
Write an expression to calculate the moment of the force at the origin
Write an expression to represent force vector.
Write an expression to represent position vector of point
Write an expression to calculate the moment of force.
Conclusion:
Substitute
Thus, the moment about origin
(c)
The moment about origin
Answer to Problem 3.20P
The moment about origin
Explanation of Solution
Write an expression to calculate the moment of the force at the origin
Write an expression to represent force vector.
Write an expression to represent position vector of point
Write an expression to calculate the moment of force.
Conclusion:
Substitute
Thus, the moment about origin is
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Chapter 3 Solutions
Vector Mechanics for Engineers: Statics and Dynamics
- Time A force F= 120 i + 240 j + 0 k (N) is applied at a point A in the x-y plane with XA 2.3 m. yA 2.6 m and ZA = 0.0 m Determine the moment (Ma) about B of the force F exerted on the point A (ie. find the components in the i. j and k direction of the moment of F about B). The coordinates of B are: X8 = 1 m, yB = 1.7 m and zg = 1.2 m All unit provided are Sl unites. Hint use the cross product YA Ye B. 20 Ma in the x (i) direction (N-m) = Ma in the y ) direction (N-m)= Ma in the z (k) direction (N-m)arrow_forwardPlease tell solutionarrow_forwardDetermine the moment about the origin of the 13 lb force whose line of action passes through points A( – 3, 6, – 6) and B( – 4, 4, 7) - M, = ( i + j+ k) lbarrow_forward
- What is the solution of this problem?arrow_forwardmy choice The moment of the force F=720-lb about the point O in Cartesian vector form is. 1 ft B 4 ft 2 ft AC A 4 ft Select one:arrow_forward2. Determine the moment of a 90 N force about point C for the condition 0 = 15°. 600mm B A 90N 800mmarrow_forward
- The moment of the force F=240-lb about the point O in Cartesian vector form is:arrow_forwardThe line of action of force F passes through points A and D. Find the component of the moment of force F about axis BC, given: F = 300 N, AX = 7 m, AY = 9 m, AZ = 9 m, BX = 6 m, BY = 6 m, BZ = 6 m, CX = 8 m, CY = 10 m, CZ = 9 m, DX = 4 m, DY = 5 m, DZ = 4 marrow_forwardThe moment of the force F=180-lb about the point O in Cartesian vector form is. 1 ft 4 ft 2 ft 4 ft. Select one: O a. Mo = 300j – 600OK O b. Mo = -200j + 400k O . Mo = -200j – 400k O d. Mo = 2003 + 400karrow_forward
- determine the general expressionarrow_forwardThe moment of the 400 N force about point O is equal to. 0.2 m 0.4 m 30 F=400 Narrow_forward3- If the two forces F, (100i - 120j + 75k) Ib and F, = {-200i + 250j + 100k) lb act at A, determine the resultant moment produced by these forces about point O. Express the result as a Cartesian vector.arrow_forward
- International Edition---engineering Mechanics: St...Mechanical EngineeringISBN:9781305501607Author:Andrew Pytel And Jaan KiusalaasPublisher:CENGAGE L