As in a lot of international schools we celebrate many different cultural days and last weekend was Holi. I'm not sure what Holi is all about except that the celebration of it involves throwing paint at people. Looking at the picture it seems that the the students opted for a clean version of Holi using water rather than coloured powder paint, maybe they didn't want to ruin the snow? The photo was taken by one of my students (Mette), she posted it on facebook and I stole it (actually I did ask but it was after the event). The thing that caught my eye in the photo was of course the parabolic path of the water. Pishun is attempting to soak Mazen although from this angle it looks like he might miss. However Pishun, being a HL physics student, has taken into account the air resistance and knows that the water will drop more sharply than one might think. Interesting how the water doesn't come out of the bucket in one go but flows out as if coming from a hose pipe. I think there is a good EE in there some where. I thought I'd try some analysis with LoggerPro to see how parabolic the path actually is. We normally analyse video with logger pro but you can use the same method for analysing stills. The equation for the trajectory is

The angle of projection is approximately 45° so this simplifies to

Here's what I got from LoggerPro

The answer to the question "did Mazen get soaked?" is yes he did but not because the trajectory was correct (sorry Pishun). The water arcing in a nice parabola isn't made of a series of particles with the same initial velocity. The water particles don't follow each other like a series of balls. The first bit is thrown with greater force than the last so the last bit of water has a much flatter trajectory. This was pointed out by Mazen and he should know.

You can see what I mean in this video (at 30s):