This tutorial will show you how to make an explosion impulsion effect with physics by just using "Apply impulse at angle" and an (animated) explosion sprite.
This effect was used in some popular physics puzzle games such as Angry Birds and Cut the Rope 2.
The magic of the explosion is:
distance(targetX, targetY, explosionX, explosionY)/threshold
The bigger the threshold, the accurate the explosion. Make it about 100-250, 100 is the recommended value.
angle(explosionX, explosionY, targetX, targetY)
The formula in the event sheet: