Pop... the perfect example of frack around and find out. In the HD version of this video you can see the projectile fly into the tank.
Btw, anyone else, when you first go to YT, and go to play a short, it plays a random different one, then if you go back, and click on the same short you wanted to watch, it plays it fine ? Its well odd, only happens on the very first short when first going to YT, also, if you copy the link of the short, and paste it into another tab etc..., it changes to a different one too, wtf is that all about