4-150. The pipe assembly is subjected to the action of a wrench at B and a couple at A. Determine the magnitude F of the couple forces so that the system can be simplified to a wrench acting at point C. Z -Fi A 0.3 m 0.3 m Fi 0.5 m -0.8 m- C 0.6 m (60k) N 0.25 m -0.7 m- D B 0.25 m {40i} N (-60k] N