Emergency help SCIENE FAIR plz

[jen8283]

HI, i have a question regarding my science fair project, im doing a project about which kind of sodas can tarnish the coin? Also i came up with the idea for the independent variable will be the types of sodas, and i planning my dependent variable will be the scales of cleaness from 1-10 but im not sure if it will work or not for my graph . can someone give me some ideas? and oh which is an appropiate site that i can get some info/sources for my science fair.
i tested the salt water with the pennies,it turned ou blue and tarnish.Also, does is matter that how dirty the penny is before you put those into the sodas?

[deleted-71553]

Hi,
You sound to me as if you are on the right track.
It is clear you are doing some good thinking about your experiment.

The dependent variable is the observation affected by one or more independent variables.
You may find this web page's description useful.
http://www.cool-science-projects.com/in ... ables.html

You may wish to make a list of the independent variables that you can think of, including those that you posted, and decide which variables you want to vary, and which you wish keep fixed (controlled) in your experiment. In an experiment, it is often important to keep as many of the things that you are not testing as constant as possible, so you are observing the effect of the variable(s) you are interested in.

You will also want to define as well as you can, before you start, the scale of your dependent variable. What are the possible things that can happen to the coin, from least/no damage to most damage? Is there anything good that can happen to the coin?

You can then use the decisions you made as a guide in planning your experiment.

Hope this helps,
Caroline

[deleted-42343]

cscolar has some good advice.

I would probably find a way to clean all the pennies so that the entire surface can be in contact with the different liquids.

You can do this as part of your procedure. I would put all the pennies in a cleaning solution of some sort (even if they aren't dirty--remember we want to try and keep as many things as possible the same for each penny). Keep them in the solution until the dirtiest pennies are clean. You could then rinse them off in water. Soap, water, and a toothbrush might be your best bet for a gentle cleaning solution. Anything acidic will ruin the pennies.

You could also just try to find pennies that are equally clean or dirty (so then they would start at the same level of dirtiness). At the bank you might be able to get a bunch of new pennies.

[deleted-37163]

Jen,

Just adding on to cscolar's and Amber's posts, one thing you could do is to try to find 10 real pennies and sort them in order of cleanliness. Then, you could compare the pennies you put in the soda to these pennies to help you measure how dirt they are in an objective way.

As Amber suggested, it would be a good idea to clean all your pennies beforehand. If this is not possible, you could also make an inital observation of each penny (1-10 on scale) and then record the change after putting them in soda.

Hope this helps,

Manjinder

[jen8283]

i put 7 coins(1976) in the same equal amount of dirty in the different kind of liquids, is this fine to do that? and then after that i observate it and put into the scale?

[deleted-71553]

Congratulations on getting your first experimental trial started!
It sounds like you are taking care to use coins in the same condition. That is a good precaution.

I'm not sure whether this has been mentioned before - it is a good idea to run the experiment more than once. Repeating the experiment allows the experimenter to start to decide whether differences between coins are due to the differences between conditions, or whether the differences are due to chance or some other extraneous factor.

[jen8283]

for my repeated trial, i used differnt years of the coin into 6 types of different drinks. Can you help me what type of graph that i can use, because my board needs to include a grph and data. My dependent is the scale of cleanness, my independent is 6 types of drinks, and the level independent ( repeated trials) is the different years of the coins(1968,1982,1995,2007,2009) that put into the drinks. should i use a bar or line graph? i dont know what other graph that i can use :[

[deleted-71553]

Hi,
There is a science buddies page discussing the use of data analysis and graphs.
It discusses what things to think about when deciding what type of graph to use.
https://www.sciencebuddies.org/science- ... ysis.shtml

Here is another web page discussing when to use different types of graphs.
http://nces.ed.gov/nceskids/help/user_g ... ntouse.asp

Hope these help,
Caroline

[jen8283]

i think i would choose to use bar graph, because line graph and other grphs doesnt make sense to graph.I think that if i using line graph, the dependent would be hard to graph, so i decided to use bar graph. What you think? pleas give me some advices. Thanks for the websites, it helped me

[deleted-71553]

It seems like a reasonable choice to me.