A transmission tower is held by three guy wires attached to a pin at A and anchored by bolts at B, C, and D. If the tension in wire AB is 840lb, determine the vertical force P exerted by the tower on the pin at A.
Write the coordinates of different points of the system.
Calculation of position vector AB and tension in AB
Calculation of position vector AC and tension in AC
Calculation of position vector AD and tension in AD
Apply equilibrium of forces
Equate the component of i in equation (1)
Equate the component of j in equation (1)
Equate the component of k in equation (1)
Solving equation (2) , (3) and (4)
The vertical force exerted by the tower is P = 1553lb