The scalar components are Fx 250 N and Fy 433 N. The vector components are Fx 250i N and Fy 433j N. Part (2). From Fig. b we may write F as F 500i N, so that the required scalar components are
Ans.
Part (3). The components of F in the x- and y-directions are nonrectangular and are obtained by completing the parallelogram as shown in Fig. c. The magnitudes of the components may be calculated by the law of sines. Thus,
The required scalar components are then
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Sample Problem 2/4
Forces F1 and F2 act on the bracket as shown. Determine the projection Fb of their resultant R onto the b-axis.
Solution. The parallelogram addition of F1 and F2 is shown in the figure. Using the law of cosines gives us
The figure also shows the orthogonal projection Fb of R onto the b-axis. Its length is
Ans.
Note that the components of a vector are in general not equal to the projections of the vector onto the same axes. If the a-axis had been perpendicular to the b-axis, then the projections and components of R would have been equal. Fb 80 100 cos 50 144.3 N
R2 (80)2 (100)2 2(80)(100) cos 130 R 163.4 N
Fx 1000 N Fy 866 N
Fy sin 60
500 sin 30
Fy 866 N
Fx sin 90 From Fig. b we may write F as F 500i N, so that the required scalar components are
500 sin 30
Fx 1000 NThe scalar components are Fx 250 N and Fy 433 N. The vector components are Fx 250i N and Fy 433j N. Part (2). From Fig. b we may write F as F 500i N, so that the required scalar components are
scalar components