Week 14: Force

Questions 

The questions that we worked on investigating this week are: 

How can a particle model help to explain 

- Why the plunger is hard to pull up when suctioned?

- Why does ice melt faster on metal than on wood?

- Why do cold drinks get water droplets on the outside?

 Plunger Experiment 

Today we spent part of lab investigating why the plunger is hard to pull up when it is suctioned to the table. The reason is that there is 14.7 psi pushing down on the plunger at all times. When the plunger is not suctioned, there is 14.7 psi also pushing up inside the plunger so it cancels each other out. When the plunger is suctioned, there is still 14.7 psi pushing down on the plunger, but now there is less than 14.7 psi pushing up inside the plunger, which is why it is hard to pull it up, you would need enough force to cancel out 14.7psi.

Model we created to explain this

Condensation on Can Experiment

Water particles in the air are a higher temperature than the cold can. When the water particles hit the can, the cold can cools it down, slowing the particle movement and allow it to create a connection. The warmer water molecules transfers heat to the cold can, essentially cooling down the water molecules and slows it down allowing it to make connections and turns into water on the can.