Science Buddies: "Ask an Expert"

which warms faster, water or soil? need ideas regarding the materials and procedure to carry the project out.

Hi,

What is the purpose of your project? Why did you want to do this? Why do you want to compare soil and water? Knowing this will help you design the best experiment. Here's a suggestion:

Let's say that you want to know how to warm soil up to the right temperature to support the germination of a particular species of seed. If you were a farmer, you could harvest an earlier crop if you could warm the soil up earlier than everyone else. Here is a website that lists optimum temperature for germination of several crops:

http://tomclothier.hort.net/page11.html

So for your experiment, pick an optimum temperature for a theoretical crop you want to plant, and then design an experiment to compare differences in temperature. You might set up several shallow boxes of potting soil in the same location with all conditions controlled (sunlight, moisture, type of soil, thickness of soil, etc) and then try to heat up the soil using different methods. You could cover one box with thin black plastic, one with thick black plastic, one with clear plastic, add some manure to one box (source of exothermic bacterial fermentation), or anything else you could think of. What would you use as a control? Be creative and do as many variations as you can think of. Then measure the temperature (in degrees Centigrade) of each box once or twice a day for a week. You will need to evaluate the way you measure the temperature and make sure your method is accurate and reproducible, since this is for a science fair project.

If you wanted to work with water samples, you could do a similar experiment and see how long it would take to warm a body of water up to a temperature that would be comfortable for swimming, for example. I can't really think of a purpose for comparing soil and water, but perhaps you had some reason for picking the topic. I think it will be sufficient for the project if you just work on one subject type, although it might be interesting to compare two different types of soil, or two types of water (e.g. fresh vs. ocean). Or, it might be interesting to set up a duplicate set of boxes and actually plant your crop and see if the theoretical temperature target matches the optimum germination rate. However, if you have limited time and resources, just limit yourself to one experiment and do a really thorough job on it.

Now, your project deadline is coming up very soon, so try to set up your experiment today or tomorrow. Allow at least a week to write up your board.

Please do let us know if you have any questions about these suggestions. And, if you did have a purpose for comparing soil and water, let me know and I'll try to think of a different experiment.

Donna Hardy

this was given to me by the teacher. i had no choice of science experiment.

Hi,

OK. This is a basic chemistry project, comparing the thermal properties of soil and water. Here's a possible experiment you could use for this project:

1. Place an equal volume of dry soil and water in identical containers. It would probably be best to use containers with a volume of a liter or larger and several centimeters deep. Place a thermal probe with a tip near the bottom of each container, ideally with a read out that you can read and record results over time. If you can get 4 temperatures probes, it would be even better if you could place a temperature probe at the top and at the bottom of each container. You can get a suitable temperature probe at a hardware store, or any large variety store that has a heating/air conditioning section. You will want to record results in degrees Centigrade, but you can convert from Fahrenheit if you have to.

2. Place a heat lamp or other source of heat a certain distance from each container. If you don't have a heat lamp, you could also do this experiment on a sunny day and use the radiant energy from the sun. Record the change in temperature over time. You will find out
if the soil or water gets hotter faster.

Now, for the science part.

Thermal energy is a form of energy that scientists measure in Joules, or kilojoules. Here is a website that describes there relationship between heat and energy:

http://www.energyquest.ca.gov/story/chapter01.html

In your experiment, you are using radiant energy from the heat lamp to transfer energy to the soil and water. The heat transferred to the water will be mixed by a process call convection when cooler liquid moves towards warmer liquid. Convection currents are circular.

The soil is a solid, and is a not a good conductor of heat energy. Materials that do not conduct heat energy are called insulators. It will probably take a lot longer for the bottom of the soil to reach the same temperature as the water sample.

If you want to get extra credit for your project, then you can repeat the experiment and cover both samples with black plastic, and white plastic.

If you want to make the experiment quantitative, you can measure the kilojoules of energy absorbed by the water. A Calorie is the amount of heat is takes to increase the temperature of 1 gram of water 1 degree Centigrade. A Calorie is 4,184 Joule. However, in order to measure the amount of heat exactly, you would need to do the experiment in a completely insulated container, so you would have to devise a different heat source, other than a heat lamp.

Remember when you do your experiment to be very careful and precise when making your measurements.

Please double check with your teacher before you proceed to make sure this is what was intended with the assignment. If this is not a chemistry project, then I may still be off-track in my advice to you. If you need more information about energy transfer or Joules, let me know.

Donna Hardy

Here's a web page with some additional info about thermal conductivity (ability of a material to transmit thermal energy) and heat capacity (ability of a material to absorb thermal energy) of different materials, including water and various types of soil.
http://www.hukseflux.com/thermal%20cond ... hermal.htm

These sorts of issues are very important in environmental science. For example, by measuring the temperature in a stream bed, you can determine the rate of flux from the stream to groundwater or vice versa.
http://pubs.usgs.gov/fs/2004/3010/

There are many other applications.

Let us know if you have any more questions!

how do you carry out an experiment?

Hi shayna / NICOLE19,

The Science Buddies Science Fair Project Guide has lots of great information that will definitely help! https://www.sciencebuddies.org/mentorin ... ndex.shtml

Information specific to carrying out an experiment can be found at: https://www.sciencebuddies.org/mentorin ... ment.shtml

But you should read all of the information provided. Hopefully, this will help!

I do have a couple of comments, though:

1) Please post your questions under a new thread to begin with, and then continue to use that same thread to post all other responses. This helps keep things together for students and experts alike who are trying to read what your project involves. Posting under a thread that has already started or is unrelated to your project (or a new thread each time) makes things difficult to follow.

2) Please do not expect an immediate response from this forum. Experts typically take 12-24 hours to respond, and maybe even longer at times. We will do our best to respond to your needs, but we do not continuously monitor this board - we all have jobs!

I hope this helps, and if you have a specific question for us, please be sure to post back under the relevant section.

Good luck!
Geoff.

Hi Shayna,

I agree with Geoff; we can help better if you let us know what your project is about this year. And you should go to the science buddies website and start a new inquiry for this year. After you read through the science buddies information for setting up an experiment, let us know what your independent and dependent variables are. Don't forget to include a control in your experiment! We'd be happy to make suggestions if we know what you are doing.

Donna Hardy

Hi NICOLE19,

Okay, I went ahead and did what you tried and came up with the following website: https://www.sciencebuddies.org/mentorin ... p023.shtml

Is this the science fair project you were wanting to do?

If so, all of the materials and experimental procedures that you asked about are contained within this link. I am unsure what it is that you are specifically requesting that is not covered. What do you expect this experiment to show, based on your background research?

Please start a NEW THREAD outlining your intended science fair project and what, specifically, you do not understand. The more information you give us, the more we will hopefully be able to help.

***Don't forget to start a new thread - do not continue to reply to this one as it was meant to be covering a topic on heat***

Hope this helps, and good luck!
Geoff.

geoffbruton wrote:Hi NICOLE19,

Okay, I went ahead and did what you tried and came up with the following website: https://www.sciencebuddies.org/mentorin ... p023.shtml

Is this the science fair project you were wanting to do?

If so, all of the materials and experimental procedures that you asked about are contained within this link. I am unsure what it is that you are specifically requesting that is not covered. What do you expect this experiment to show, based on your background research?

Please start a NEW THREAD outlining your intended science fair project and what, specifically, you do not understand. The more information you give us, the more we will hopefully be able to help.

***Don't forget to start a new thread - do not continue to reply to this one as it was meant to be covering a topic on heat***

Hope this helps, and good luck!
Geoff.

Geoff,

The new thread is at:
https://www.sciencebuddies.org/mentorin ... php?t=3147

I copied your answer over there, since it contained information about the project.


Louise