Question

3. A 19.0 kg mass is hanging from a point 0.8 of the way up a 9.0 kg, 2.3 m long uniform beam
that is attached at a 50 angle to a vertical wall as shown above. One end of a cable is attached to
the end of the beam, while the other end of the cable is attached to the vertical wall at an angle of
70. Find the tension in the cable.

Answer 1

Torque about any point in the space will be zero

Explanation:

Please find attached the free body diagram of the beam.

We find that the system is in static equilibrium. Therefore, the torque about any point in the space will be zero.

Let's find the moment about the joining point of the vertical wall and the beam.

Σ = 0

From the figure, we get:

(mg.sin50°) (0.8l) + (m`g.sin50°) (l/2) - (T.Sin20°)l = 0