Science Buddies: "Ask an Expert"

I am doing the Science Fair CSI: Can You Predict the Spatter? project and I am having trouble with my origin points. So far I have done two tests from different distances (58 and 258 mm. from the corner) and i have found the angle of Impact as well as plotting them with string. I am done with two of my three tests and the string never lands on the sponge. Sometimes two droplets will have the same calculated origin point but I think I'm doing something wrong on account of the string/twine never hitting my actual origin point. Am I doing something wrong? If so what?

Hello,
You have probably made pretty accurate measurements and calculations if you found that the drops have the same angle of impact and origin point. I would try drawing strings from as many droplets as possible to find the truest origin. Step 11, which says "Do the strings converge at the location where you hit the sponge? ...What is the difference in actual location and the calculated location?" seems to suggest that it is okay to have some difference between the location of the sponge and the point of convergence of the strings. As always, the best way to obtain meaningful results is to complete numerous trials, so just try again if you really are not satisfied.
I wish you luck!

Cgiara is probably correct.

Excuse me, Chiara is correct. (Typo)

Thank you, but any new answers would be welcomed.

Hello TAG24,

Since I can't see your splatters or the other aspects of your setup, I really can't know what might be going wrong.

One method to figure out how an experiment might be failing is to use "test data." In other words, instead of pretending that you don't know the position of the sponge and trying to deduce it from the spatters, consider that you do in fact know where the spatter drops came from. Pick one spatter and compare its shape to what you would calculate the shape to be from the known source.

Is the drop the shape you expect? If yes, then when you retrace the path, it should go back to the sponge. If the shape is not as expected, then examine your setup and figure out why the spatters are not shaped as expected.

Good luck, WW