The pipe assembly is subjected to the force of F 650 i 750

The pipe assembly is subjected to the force of F = {650 i + 750 j - 600 k) N. Determine the x, y, and z components of the moment of this force about point B Express your answers using three significant figures separated by commas

Solution

point B = (0.5,0,0) and Point C = (0.5, 0.7, -0.4)

BC vector = (0.7j -0.4k)

F = 600i + 750j - 600k

M = FXBC = (600i + 750j - 600k)X(0.7j -0.4k)

= i (750·(-0.4) - (-600)·0.7) - j (600·(-0.4) - (-600)·0) + k (600·0.7 - 750·0) = i (-300 + 420) - j (-240 + 0) + k (420 - 0)

= {120i + 240j + 420k}