A couple weeks ago, I came home after a long day at work looking for a break. I thought to myself, “What’s more fun than physics? Batman*.” I sat down to play the latest Batman videogame, in which Batman’s current objective was to use his grappling hook to jump onto an enemy helicopter to steal an electronic MacGuffin. As awesome as this was, it occurred to me that something was very wrong about the way the helicopter moved while Batman zipped through the air.
See if you can spot it too. (Watch for about 5 seconds after the video starts. Ignore the commentary. Note: The grunting noises are the sounds that Batman makes if you shoot him with bullets.)
What occurred to me was this: If the helicopter’s rotors provided enough lift to balance the force of gravity, wouldn’t Batman’s sudden additional weight cause the helicopter to fall out of the sky? Also, to get lifted up into the air, the helicopter must be pulling up on Batman: shouldn’t Batman also be pulling down on the helicopter? By how much should we expect to see the helicopter’s altitude change?