Flow of sand and a variable mass Atwood machine

J FLORES; G SOLOVEY; S GIL

AMERICAN JOURNAL OF PHYSICS

AMER ASSOC PHYSICS TEACHERS AMER INST PHYSICS

Año: 2003 p. 715 - 720

0002-9505

We discuss a simple and inexpensive apparatus that lets us measure the instantaneous flow rate of granular media, such as sand, in real time. The measurements allow us to elucidate the phenomenological laws that govern the flow of granular media through an aperture. We use this apparatus to construct a variable mass system and study the motion of an Atwood machine with one weight changing in time in a controlled manner. The study illustrates Newton’s second law for variable mass systems and lets us investigate the dependence of the flow rate on acceleration.