A scaffold of mass 60 kg and length 5.0 m is supported in a horizontal position by a vertical cable at each end.A painter of mass 80 kg stands at a point 1.5 m from one end.

Question

(a)Find the tension in the cable nearer to the painter.
(b)Calculate the tension in the second cable

Answer 1

(a) Set the moment about the cable support point at the opposite end equal to zero. The scaffold weight force acts as if applied at the center.

3.5*M1*g + 2.5*M2*g - T1*5 = 0

Solve for T1, the tension on the cable nearest the painter. M1 is the painter's mass and M2 is the scaffold mass.

2. T1 + T2 = (M1 + M2) g
(This statement says that the net vertical force is zero).
Solve for T2.