Question

Knowing that angle = 55 and that boom AC exerts on pin C a force directed along line AC, determine (a) the magnitude of that force, (b) the tension in cable BC.

Answer 1

Draw free body diagram at point C as shown:

$C:\Users\masada.rajesh\Desktop\1.jpg$

From the Lami’s theorem, write the equilibrium equation of forces as follows:

…… (1)

Here, is the tension in the cable BC and is the force in the member AC.

(a)

Calculate the force in the member AC as follows:

From equation (1),

Here, the negative sign indicates that the original direction is opposite to that of assumed direction.

Therefore, the force in the member AC is

(b)

Calculate the tension in the cable BC as follows:

From equation (1),

Therefore, the tension in the cable BC is .