Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.

A ruler with variable mass density

A ruler is exactly L = 6 inches long. It has a linear mass density which increases from one end of the ruler to the other:


   60 g/inch    for the first inch
   70 g/inch    for the second inch
   80 g/inch    for the third inch
   90 g/inch    for the fourth inch
  100 g/inch    for the fifth inch
  110 g/inch    for the sixth inch




  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 red box.



  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

Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.