There are a few things that blow up, specifically: exppacks, grenades, bazooka shells, landmines, katyusha rockets, flak gun shells, and depth charges. This value is the force that these explosives cause to push enemies around. The Material of an explosive is what causes actual damage (see the Damage Tutorial).
Typical values: 50 for exppacks, 30 for landmines, 15 for katyushas, 10 for grenades, 2 for bazookas, 1 for flak. So exppacks are much better than bazookas for launching people into the air.
Source and more details