Many people are mesmerized by the special effects in action movies these days. "How did they do that?!" is a comment I frequently hear after a good action flick. I try my best to not turn around and say, "Well, simple. They just made a naphthalene/black powder 'salt & pepper' mix, and shot the 'bazooka' rocket across a zipline, leading up to the nap charge, and..". When I did this I received many strange, somewhat freaked-out looks. So, I stopped doing that, and, being the cynical person that I am, occasionally told them to read a book on it, with or without the occasional muttering of 'ignorant wankers'. However, it seems I have found an audience who will actually listen to my 'sermons', and not get bored and/or scared. So, once again, I've decided to illustrate the classic 'bazooka is shot at a building, the rocket hits it and blows it up' scene.
This effect is very easy to recreate. A mock-up of a bazooka is filmed firing, using a flash/smoke charge. In the next scene, a zipline rocket is shot across a taut wire and it impacts the building. The most difficult part of it is to make the naphthalene explosion occur at the exact moment the rocket hits the target surface. This can be done with a push button-ignited e-match and quick reflexes.