Problem Description

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A luggage transport system for a new airport is having some problems. The railway track bends when the luggage carrier passes over it and will probably break. To analyze this bending, engineers must determine the neutral axis of the beam, which for a homogeneous beam passes through the centroid of the cross section. (The area moment of inertia of the cross section will be found in a latter section).

What is known:

  • The dimensions of the cross section are as shown.

Rail Cross Section


Where is the centroid of the cross section?


  • Break the beam cross section into simpler, component parts.
  • Determine the centroid and area of each component part.
  • Use the method of composite parts to calculate the x and y locations of the centroid of the cross section.