I'll include the source file download below..
This example shows a simple Explosion with physics now with Impact added! I simply used two variables to the explosion, the Impact size (as you see in the picture) get's set to 20 (twenty) upon it's creation, that's an average small sized Impact.
For those who lack knowledge on what "Impact" means in this example, It's the objects it affects around the explosion and not just the ones it touches.
In this example it doesn't show but the explosion visual has to be seperate, this "RedBlock" in this example is the Impact source for the explosion.
Click here to Download the Source file (Main)
Click here to Download the Source file (Mirror)