A ruler with constant mass density (again)

A ruler is exactly L inches long. It has a linear mass density of λ grams per inch.



  Q:  What is the mass of one inch of the ruler?


  Q:  What is the total mass of this ruler?

The answers

Now, let's consider one little piece of this ruler: I'll mark it with a dark blue color.



  Q:  What is the mass of this little piece?


  Q:  What is the contribution of this little piece
          to the equation for center of mass?


  Q:  What is the location of the center
        of mass of the ruler in the horizontal direction?

The answers