Thermodynamics B/C

[Bobbycat]

I keep seeing people post asking for results. I would be willing to share but if post and ask but are not sharing that is not equitable. So if you want results, post some results.

[antoine_ego]

I keep seeing people post asking for results. I would be willing to share but if post and ask but are not sharing that is not equitable. So if you want results, post some results.

Often, people who ask for results haven't yet completed their builds and simply are wondering what level to shoot for. People post their results because they're interested in helping others by giving them an idea of what a good score is or highlighting potential troublesome issues in construction. Furthermore, I recall seeing people posting their scores earlier in the thread so if you're interested I'd recommend reading through them all.

[jaah5211]

I was reading the rule book and was wondering what percentage of the points are dependent on the written test portion. Can anyone answer this?

[Unome]

I was reading the rule book and was wondering what percentage of the points are dependent on the written test portion. Can anyone answer this?

See rule 5.c.

[appleshake123]

Our highest was (150ml at 90 C) 64 degrees. I find that the best way to do predictions is to:
1.)Gather data for each water interval ( 50,75,100,125,150 at invitationals B division)
2.)At each water interval, collect data for temperatures 60,70,80, and 90 degrees Celsius temperatures
3.)Get out a graphing calculator or other software and find the quadratic regression curve for each water interval (starting temperature v ending temperature)
4.)Use quadratic equation and generate table for each amount of water

What are you using to heat up the water. Also, when we test, the time it takes from pouring the hot water into our beaker and putting it in our device, the temperature drops significantly. For example, say I heat up the water to about 93 C, in 5 seconds out of the pot, it goes down to 86 C. So, how are you guys testing.

The rules (high school at least) say you are allowed to measure the temperature of the water after pouring it in. I would measure it after pouring it into your device both while testing and at competitions.

Definitely have a thermometer of your own to measure the initial water temperature inside of your beaker. For a 65 C water pot at 100 ml, the water decreased to around 58 C in my beaker, so at least make sure to account for a drop in initial temperature. At 100 C, between scooping the water then into the beaker, the 100ml went down to 86 C which then, after 30 minutes, decayed to 74 degrees.

For such a large time constant for your box, a linear or quadratic or exponential curve works. I know for my box, an exponential curve fit right along Newton's law of cooling derivation(mostly due to conduction). I advise using excel or a similar spreadsheet for data collection because your data is then stored in a more secured location without risk of accidentally deleting it.

[vb]

What are you using to heat up the water. Also, when we test, the time it takes from pouring the hot water into our beaker and putting it in our device, the temperature drops significantly. For example, say I heat up the water to about 93 C, in 5 seconds out of the pot, it goes down to 86 C. So, how are you guys testing.

The rules (high school at least) say you are allowed to measure the temperature of the water after pouring it in. I would measure it after pouring it into your device both while testing and at competitions.

Definitely have a thermometer of your own to measure the initial water temperature inside of your beaker. For a 65 C water pot at 100 ml, the water decreased to around 58 C in my beaker, so at least make sure to account for a drop in initial temperature. At 100 C, between scooping the water then into the beaker, the 100ml went down to 86 C which then, after 30 minutes, decayed to 74 degrees.

For such a large time constant for your box, a linear or quadratic or exponential curve works. I know for my box, an exponential curve fit right along Newton's law of cooling derivation(mostly due to conduction). I advise using excel or a similar spreadsheet for data collection because your data is then stored in a more secured location without risk of accidentally deleting it.

Your results look impressive.. What have you used for constructing the box?

[JoeyC]

Hey if you are willing to share, what are you guys getting with the conditions from above? We got 64 C, what are you guys getting.

Our highest was (150ml at 90 C) 64 degrees. I find that the best way to do predictions is to:
1.)Gather data for each water interval ( 50,75,100,125,150 at invitationals B division)
2.)At each water interval, collect data for temperatures 60,70,80, and 90 degrees Celsius temperatures
3.)Get out a graphing calculator or other software and find the quadratic regression curve for each water interval (starting temperature v ending temperature)
4.)Use quadratic equation and generate table for each amount of water

What are you using to heat up the water. Also, when we test, the time it takes from pouring the hot water into our beaker and putting it in our device, the temperature drops significantly. For example, say I heat up the water to about 93 C, in 5 seconds out of the pot, it goes down to 86 C. So, how are you guys testing.

I usually just microwave it to a high temperature, wait til it cools down to my desired temperature, then quickly put it inside the device. (but because I microwave it my water ,and henceforth my device, smell "dead")

[JoeyC]

I started this event thinking, "Hey, insulate a beaker, sounds intriguing, I'll try this out, doesn't sound to complex,"
Now: is studying college level science and figuring out how much energy in joules seeps through a 2 inch thick wall with thermal conductivity of 2.34 with temperatures on either side being 61 and 83 degrees celsius

Science Olympiad; you'll be ready for college

[appleshake123]

The rules (high school at least) say you are allowed to measure the temperature of the water after pouring it in. I would measure it after pouring it into your device both while testing and at competitions.

Definitely have a thermometer of your own to measure the initial water temperature inside of your beaker. For a 65 C water pot at 100 ml, the water decreased to around 58 C in my beaker, so at least make sure to account for a drop in initial temperature. At 100 C, between scooping the water then into the beaker, the 100ml went down to 86 C which then, after 30 minutes, decayed to 74 degrees.

For such a large time constant for your box, a linear or quadratic or exponential curve works. I know for my box, an exponential curve fit right along Newton's law of cooling derivation(mostly due to conduction). I advise using excel or a similar spreadsheet for data collection because your data is then stored in a more secured location without risk of accidentally deleting it.

Your results look impressive.. What have you used for constructing the box?

A medicinal styrofoam box with cottonball stuff around teh beaker with a cap: a very simplistic design for now.

[arv101]

I started this event thinking, "Hey, insulate a beaker, sounds intriguing, I'll try this out, doesn't sound to complex,"
Now: is studying college level science and figuring out how much energy in joules seeps through a 2 inch thick wall with thermal conductivity of 2.34 with temperatures on either side being 61 and 83 degrees celsius

Science Olympiad; you'll be ready for college

Haha so true, only in college and engineering you'll have to worry about the insulation material not being perfect, the temperature of the table, light, etc. Also, instead of insulation hot water, try a nuclear reactor !