how create a explode force collider

I don't quite understand what you mean, force and colliders are different things.

If you wanted objects to fly away from the explosion you just give them rigidbodies and then set the force variable on the detonator prefab to true.

EDIT:

Considering your "answer" you're looking for collision relative velocity:

http://unity3d.com/support/documentation/ScriptReference/Collision-relativeVelocity.html

thx, for the answer.

i need the force value in the object that collide with force.

i want decrease life from this object. more force decrease more hp