Saturday, April 16, 2011

How do you crush your cans?

This is what I do. Here's the procedure:


  • Place 8-10 ml of water in an empty pop can.

  • Place the pop can onto the heat source and wait for the water to boil. After you see steam escape, continue to boil for one minute.

  • Use the tongs to remove the can from the heat. Quickly turn it upside-down and place it into a saucer with water (which was close-by).

As Mr. Hoegh goes through this lab demonstration, please answer the following questions in a blog comment.



  1. When heating, what kind of air pressure was inside the pop can -- high or low? Explain why you believe this to be true.

  2. Once the heated can was placed into the water, what kind of air pressure was on the outside of the can -- high or low?

  3. What caused the can to be crushed? Why did we need the water seal?
After completing these questions in your comment, go through some "Pressure" flash cards on Ediscio, or look at the following pressure websites. Otto von Guericke makes a vacuum Toricelli's Barometer video Air Pressure Balloon Animation Storm System Animation

33 comments:

Katie T. said...

1. Low because high pressure rose with the warm air
2. High
3. The high pressure caused the can to crush cuz the water blocked the space for the air to get out

Mercedes D. said...

1) There is low pressure because the air is hot.
2) High pressure because the air is cold.
3) The differences in pressure crushed the can. It needed a seal so the air couldn't escape.

Adriahna said...

1. Low because warm air has low pressure and the can was filled with warm water

2. High, because it was put into cold water which has a higher pressure

3. It crushed because the warm air didn't have any further to go up. And the water seal kept the warm water evaporation from going up so it shriveled up and popped

Nevada renner said...

low pressure becuz it was warm air and warm air rises. so less air particles, so high pressure outside of the can also when the can hits the high pressure from the cold air which causes the can to crush. the water seal helps the low pressure leaves as quickly. so thn the can still crushes but slower becuz it doesn't have as much cold pressure gokn inside at one time.

Adam A. said...

1. It had low pressure inside the can because the water evaporates into warm water vapor.

2. High pressure because it was placed in cold water, which has more density than hot water.

3. The difference in pressure caused the can to be crushed.

adam k said...

low because it is hot and it is going to the colder outside of the can.

2high preesure

3 i think it was because it was a quick change in temperature then the water vapor turned to water and used less area.

Alexis R. said...

1. Low pressure was in the pop can, I believe this because it was heating and hot water has low pressure.
2. When it was put in the water there was high pressure outside the can.
3. The high pressure around the can caused it to be crushed, we need the water seal because otherwise the warm water would escape and the can wouldn't have crushed.

Emily Wagner said...

1) Low pressured because the air is hot ( which equals low pressure) and the air is escaping through the top of the can.
2) High pressure
3) air always moves from high pressure to low pressure, so the air on the outside of the can tried to get into the low pressure, but the water seal blocked it's only entry, so the can was crushed by the high pressure as a result of this

Damian G. said...

1) Low pressure because hot water has low pressure and hot particles move everywhere faster.
2) Low pressure because the water and the can were being heated and hot stuff has low pressure.
3) When the high pressure of the cold water was trying to get to the warm low pressure water, it crushed the can in order to get to the low pressure.

Abby B. said...

1.) There is high pressure because the molecules in the popcan are moving quite fast when the pop can is being heated.

2.) High


3.) High pressure combined with low pressure caused the can to be crushed when it entered the water. The water seal kept the air from escaping.

Kristie m said...

The air pressure was low because hot air has a low pressure.

High pressure wAs on the outside if he can

The combining pressures caused the air to be crushed. The seal was needed to keep the hot air in

Ben to the Jammin to the Hanzen said...

1.) high pressure because the molecules inside are moving so quickly

2.) high!

3.) the high pressure on the outside of the can pressing against the low pressure inside the can. We need the water seal to trap the molecules inside the can and cause low pressure.

Kelsey R. said...

1.the can had low pressure when it was heating. Because it was warm and being heated.
2.the can had high pressure around it.
3.having no air pressure is what caused the can to be crushed. And you need the water seal because otherwise the air pressure would change.

Imrann G and Murad I said...

1. when the can is on the grill it has high pressure
2. High
3. As the can got off the heater it was losing pressure. Then outside pressure was high. And air travels from high to low. Thus crushing the can.

Ashley Zimmer & Anna Mahowald said...

1. Low pressure was in the pop can when heating because high temperature is low pressure
2. It is also low pressure on the outside of the can because the air and the water is hot around the can.
3. The difference in air pressure between the water out of the can and the water in the can. The water seal was to trap the low pressure and heat in the can.

Eric Sanchez said...

low pressure because heat goes low and it would stay warm.

2.high because outside the can it was hit by cold which let out the low air of heat and made it of high heat.

3.Because of the heated air and scince it was low and went to high it let out all of the air pressure.

Tyler hofer said...

1.The can has high pressure because of it sitting on the heater. 2. High 3. The can was crushed because of all the air pressure was filled up and the water wouldn't let it out so when the water got out of the can it exploded

Tyler u said...

High pressure

low pressure

the rapid change of pressure, so the water could evaporate and still have the water vapor inside the can and so no air could go in

Brock kortan said...

Low pressure bcause as soon as you put it in cold water the high pressure from I crshed the can

high pressure because that then crushed the can

as soon as the low pressure was trapped then it stared to cool and as it cooled the pressure became higher then became tomuch for the can and crushed it

Sam l said...

1.Low because there was more heat when the can was being heat and heat contains low pressure
2.high pressure is found in cold things such as ice cold water so there was high pressure
3.when the can goes into the cold water it gets crushed because there is only water vapor in the can

Kyle Hess said...

1. The pressure was low because the air was hot and warm air has low pressure.
2. High
3. The can was crushed because the water seal prevented the high pressure air from moving to low pressure so the high pressure crushed the low pressure.

Alex Boerema said...

1.low pressure was inside the can because the molucuales were heated causing the molucuales to speed up.
2.High pressure was on the can.
3.The can became crush because the air on the inside could not escape and the air on the outside push in so the can was crushed. So the air could not escape.

Kahlen Morris said...

1.) low pressure because it was heated
2.) high pressure
3.) the air was moving fast and when the seal was applied the air could not escape so when it cooled it took up less space making the Pressure to over power the can

Austin C said...

1. Low pressure, since the can was heated that creates a low pressure.
2. High pressure, since the can was put in cold water it
cools the can faster and makes it high pressure.
3. The sudden change from low pressure to high pressure crushed the can.

Brita C. said...

1.There was low pressure in the can because there was warm air the can. Warm air provides low pressure because it is less dense than cool air because warm air rises and cool air sinks. The reason for the air in the can is because it was sitting on a Bunsen burner.
2. There was high pressure being applied to the can when it was placed in the cold water. This is because cool air sinks because it is more dense than warm air because as we know warm air rises and cool air sinks.
3. The can was crushed by the changes in the pressure and temperature. When the can was placed in the cool water the warm water vapor changed back into water because it was placed in the cold water. This change then took out the air in the can and it was crushed by the push of the air. We needed the water seal because we did not want any of the air to escape out of the can or entering the can. This would change the results of this experiment.

Taylor L. said...

1.There is high pressure inside the can because the pressure is heated and is using the water inside the can to cause the high air pressure. 2.the outside of the can has low pressure because the can itself has no pressure on the outside of the can. 3.the can crushed because the fast change of air pressure caused the can to aitomaticlly crush

Megan H said...

1. I think it is low pressure because the inside is hot. 2. High pressure because it was placed inside cold water and cold is high pressure. 3. The can was crushed because there was no pressure left inside the can.

Kelli S. said...

1)Because high temperatures have low pressure, the can had low pressure during heating.
2)When the can was placed in the ice water, it was immediately surrounded by high pressure, because high pressure is found in cold places.
3)The can was crushed because no hot air could enter the can after the water seal was on it. The cold air was high pressure and was able to displace the hot air and prevent any more from entering, and therefore, the can was crushed.

Lukas nelson said...

1Low becausethe air is hot
2low because the water is heating up
3the expanded air compressed back into the can
there must be a seal so no air can come back in

Hannah A said...

1. high - because high pressure is warmer.
2. low - because the pressure inside the can is high rather than around it.
3. because no air could get inside, and the pressure differences collided.

Madison T said...

1. There is low pressure inside the can when heating because high temperatures have low density and low density means that the particles are spread new apart, creating low pressure. 2. There was high pressure on the outside of the can because it is cold and cold temperatures results in high density which is when the particles are more closley together, creating a high pressure. 3. The can wad crushed because when the can was on he boiler, all the hot water turned into water vapor and then when put into he cold water, the waeer vapor on the inside condensed back into water, taking up less space. Also, since it was hot on the inside and cold on the outside, it was high pressure on he outside and low preside on the inside, which leads to the. high pressure crushing the low pressure.

Alexis I. said...

1. The hot air that is in the pop can during the heating process contains high pressure because it's high temperature is keeping it inflated.
2. The pressure once placed in the water was low and that is why it collapsed.
3. The fast movement of pressure from high to low caused the can to be crushed because it was a quick difference. The water seal keeps the hot air inside and cold air outside in order for it to react the way it did.

Katlynn p. said...

1. Low air pressure because low air is always Werner and there is warmer air in the can because it's heating up.
2. High air pressure because it cooler air around the can.
3. The can crushed because there was no more air in the can... Only water vapor so there fore when placed inside the water it cushes it because there's no air.

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