The log is being towed by two tractors A and B. Determine the magnitudes of the two towing forces F_A and F_B if it is required that the resultant force have a magnitude F_R = 10 kN and be directed along the x axis. Set θ = 15°.
Solution:
Let us first draw the vector components.
Now, we can draw the vectors tail to tail as follows:
From this, we can easily figure out F_A and F_B using the law of sines. (Forgot the law of sines?)
\frac{F_A}{\sin15^0}=\frac{10}{\sin135^0}
F_A=3.66kN
\frac{F_B}{\sin30^0}=\frac{10}{\sin135^0}
F_B=7.07kN
This question can be found in Engineering Mechanics: Statics (SI edition), 13th edition, chapter 2, question 2-17.