A Model Oil Well

Expected Responses:

1. When the funnel was above the level of the sand, water rose in the second tube.
   
   
2. The Plasticine acts as a seal. If it was not there water would rise freely through the gravel and sand.
   
   
3. By blowing into the funnel pressure is added. The pressure is transferred to the fluid in the gravel layer (reservoir) and speeds up the flow (movement) of the water toward the exit tube.
   
   
4. The liquid could be removed by applying suction, i.e. pumping.