The students conducted an experiment to show that a steel ball is denser than lentils and sinks when shaken in a mixture. They placed a ping pong ball between lentils in a bowl, then added a steel ball on top. When shaken, the steel ball sinks below the lentils while the ping pong ball rises to the surface. The experiment demonstrates that denser objects sink in granular materials like lentils due to the Brazil nut effect, where larger particles rise to the top during vertical vibrations.

1. EXPERIMENT: A SEA OF LENTILS
Made by:
Pablo Fernández
Álvaro Ortiz
Pablo Rodríguez
Raúl Paciencia
Francisco Javier Navarro
Colegio Maristas Badajoz Start date: 15 december
End date: 19 december

2. What do I intend to show?
That the steel ball is denser than the lentils and sinks when shaking the
mixture.
Hyphotesis
• We fill a bowl with lentils leaving a ping-pong ball caught between the
lentils. Then place a steel ball on the lentils.
• If we shake the container we see that the steel ball sinks and the ping-
pong comes to the surface.

3. Materials
To perform our experiment we need a container with lentils, a steel ball and a
ping-pong ball.
Experience
We liked the experiment. It is very entertaining.

4. We see how to put them in water the one of iron sinks and the one of ping-pong
floats.
Let's see what happens when we put the ping-pong in the lentils ...

5. And we put the lentils on it until it is covered by them.
When we put the iron on and shake the bowl ...

6. We see that the ping-pong ball comes to the surface
while the iron sinks into the lentils.

7. VIDEO DEMONSTRATION

8. Conclusions
• When shaking the bowl the ping-pong ball generates a
hole beneath it that is occupied by the smaller lentils.
Such lentils prevent the ping-pong ball from regaining
its original place and an upward movement is
generated.
• This phenomenon, characteristic of the granular
matter, is called the effect of Brazil nuts and consists of
the tendency of larger particles of a mixture to ascend
to the surface when the mixture is subjected to vertical
vibrations.
• The steel ball is denser than the lentils and sinks by
stirring the mixture.

9. Bibliography
Arróspide-Román, M. C. 2016. Física y Química. Química
E.S.O. 2. Proyecto Somos Link. Edit. Edelvives. 10-49.
Cedeño González, F. O., Prieto González, M. M., Bada Gancedo, J. C., & Alonso Suárez,
R. (1999). Estudio de la densidad y de la viscosidad de algunos ácidos grasos puros.
Webgraphy
http://fq-experimentos.blogspot.com.e s/2016/02/376-
un-mar-de-lentejas.html
From here we have extracted all the information from the experiment.
JERONIMOMM@MARISTASMEDITERRANEA.COM
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