The three cables are used to support the 40kg flowerpot Dete
The three cables are used to support the 40-kg flowerpot. Determine the force developed in each cable for equilibrium.
Solution
AC is along +ve x axis.
Fac = Tac i
Ab is along +ve y axis.
Fab = Tab j
AD is in the direction of -1.5i - 2j + 1.5k
unit vector = (-1.5i - 2j + 1.5k ) / sqrt(1.5^2 + 2^2 + 1.5^2)
= - 0.514i - 0.686j + 0.514k
Fad = Tad ( - 0.514i - 0.686j + 0.514k )
and gravitation force, Fg = 40g (-k)
Fg = - 392k N
balancing force,
Fnet = Fab + Fad +Fac + mg = 0
Tac i + Tab j + Tad ( - 0.514i - 0.686j + 0.514k ) - 392k = 0
Tac - 0.514Tad = 0
Tab - 0.686Tad = 0
0.514Tad - 392 = 0
Tad = 762.6 N ........Tension in AD cable.
Tab = 0.686 x 762.6 = 523.17 N ...Tension in AB
Tac = 0.514 x 762.6 = 392 N ---- Tension in AC
