Sarahlopez
Posts: 2
Joined: Mon Oct 20, 2014 6:26 am
Occupation: Student: 11 grade

I need help with my background research

Postby Sarahlopez » Mon Oct 20, 2014 6:38 am

"Do mints actually cool hot water down? "

Above is my testable question for my science fair project.
I am working on background research but, i can't find any information that are useful or able to answer my testable question. Can anyone help me?

tdaly
Former Expert
Posts: 1415
Joined: Sat Nov 08, 2003 11:27 pm
Occupation: Planetary Scientist

Re: I need help with my background research

Postby tdaly » Fri Oct 24, 2014 7:51 am

Hi Sarahlopez,

Can you please elaborate on what your experiment will involve? What is your hypothesis and why do you think your hypothesis will be correct? With this additional information, we'll be able to help you much more effectively. In the mean time, you can look up some background information about specific heat and temperature changes in water. Here is one link to get you started.

http://hyperphysics.phy-astr.gsu.edu/hb ... /spht.html

I look forward to seeing some additional details about your project!
All the best,
Terik

Sarahlopez
Posts: 2
Joined: Mon Oct 20, 2014 6:26 am
Occupation: Student: 11 grade

Re: I need help with my background research

Postby Sarahlopez » Mon Oct 27, 2014 6:05 am

Hi Terik Daly,

Thank you so much for taking in trying to help me with my science fair.
The link below will show you show you what my experiment looks like as well as my hypothesis.
So far, I have written some information for my background research but I don't feel confident with what I have.

https://docs.google.com/a/students.logo ... QPu_s/edit

Thank you again for helping me.

Sarah L.

tdaly
Former Expert
Posts: 1415
Joined: Sat Nov 08, 2003 11:27 pm
Occupation: Planetary Scientist

Re: I need help with my background research

Postby tdaly » Mon Oct 27, 2014 7:24 am

Hi Sarahlopez,

Thank you for this additional information - it certainly helps to clarify things! Your background research on the first law of thermodynamics is headed in the right direction. I suspect part of why you are having trouble finding background information is that the outcome of your project is related to the mass and temperature of what you add to the water, not the fact that your are adding mint. For example, you could get a similar result by adding an equal mass of candy bar that has been stored at the same temperature as your Mentos. That doesn't make your project any less interesting, but it does help to focus your background research.

The change in temperature of the water depends on the amount of energy transferred from the water to the Mentos, as well as something called the "heat capacity" or "specific heat" of the water. Have you learned about heat capacity in any of your classes? If not, then the link I included in my first reply is a good place to start learning about heat capacity. A technique called "calorimetry" (loosely, the measurement of heat transfer) is also relevant to what you are doing. These two web pages can get you started:

http://dwb4.unl.edu/chem/chem869w/chem8 ... fo014.html
http://www.physicsclassroom.com/class/t ... alorimetry

In brief, temperature is a measure of the average kinetic energy of the molecules in a material. When you add the Mentos to the water and they dissolve, the heat that is transferred from the water to the Mentos decreases the average kinetic energy of the water + Mentos system, decreasing the temperature of the water.
All the best,
Terik


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