Please Solve This Physics Problem

Question

A horizontal beam of length 4 m and mass 8.0 kg has a mass of 3.0 kg and width 0.8 m sitting at the end of the beam. What is the torque due to gravity (in N · m) on the beam–block system about the support at the wall? (Enter the magnitude.)

Answer 1

The Torque, τ, for the beam can be found by assuming that all of the mass is acting at the center of gravity.

Likewise for the mass supported at the end of the beam.

In this situation, the radius of the torque for the beam is 2 m, and for the supported mass is 3.6 m (length of the beam - 1/2 the width of the mass for its center of gravity)

Torque is Force x radius. Sum the torques of each mass.