Both videos are part of Just Cause 2's 'Anatomy of a Stunt' series. The first, called 'Using Gravity to Eliminate Enemies' summarizes the subtleties surrounding Newtonian principles, and how players can use those principles to dispatch enemies with style.
BOOM video 4096
The second trailer in the series is called 'Destroying Fuel Tanks', but it could just as easily be called 'Jumping Over Exploding Tanks of Jet Fuel While Standing on the Hood of a Sports Car in a Way that Would Make Evel Knievel Feel Like a Wuss.'
BOOM video 4101
Just Cause 2 parachutes on to PC, PlayStation 3, Xbox 360 on March 23.