Free body diagram for dry ice subliming in a sealed bottle

[tremain74]

Homework Statement

I have a problem where you have a plastic bottle of dry ice. As you put warm water into the bottle, dry ice is converted into dry ice. I want to see if my free body diagram makes any kind of logical sense.

Relevant Equations

I used Newton's second law of motion: Force = mass * acceleration.

This is my attached picture.

 

[phinds]

dry ice is converted into dry ice

Doesn't sound like a very interesting conversion. The process would be "do nothing".

 

[tremain74]

Doesn't sound like a very interesting conversion. The process would be "do nothing".

Actually, I meant that the dry ice is converted into carbon dioxide. My apology.

 

[Baluncore]

A water-iceberg, floating in a liquid sea of salt solution, is converted into a smaller iceberg, and a more dilute, cooler liquid ocean.

A dry-iceberg floating in warm water, is converted into CO₂ that escapes, and cooler water that eventually may partly freeze, then thaw.
The more dense CO₂ gas, first displaces the air, then overflows the bottle.
The dry-iceberg cannot be coated in water ice, because that is pushed off by the CO₂ sublimed.

Is your FBD modelling icebergs, that are changing their mass by melting or subliming, while floating and being buoyant in changing density fluids?

 

[tremain74]

A water-iceberg, floating in a liquid sea of salt solution, is converted into a smaller iceberg, and a more dilute, cooler liquid ocean.

A dry-iceberg floating in warm water, is converted into CO₂ that escapes, and cooler water that eventually may partly freeze, then thaw.
The more dense CO₂ gas, first displaces the air, then overflows the bottle.
The dry-iceberg cannot be coated in water ice, because that is pushed off by the CO₂ sublimed.

Is your FBD modelling icebergs, that are changing their mass by melting or subliming, while floating and being buoyant in changing density fluids?

My free body diagram doesn't include the ice that comes as a result of water that will eventually freeze. However, in reality, I definitely have to include the ice in the fbd as well.

 

[Baluncore]

However, in reality, I definitely have to include the ice in the fbd as well.

A wet ice lump, floating in a glass of cold water, will gradually melt, but the water level in the glass will stay practically the same throughout the process.

Big bits of dry ice sink in water. Small bits also sink, but then float as they sublime, as they are buoyed up by the attached gas bubbles. A fog will form near the surface of the water. Your FBD will need a little more complexity.

Maybe you should first decide why you need an FBD, or what you are trying to model.