Why do my objects floating constantly using AddExplosionForce?

Hey folks,

I’ve created an object which explodes OnTriggerEnter.
It gathers the colliders of all objects within the explosion radius. It applies explosion force to them:

targetRigidbody.AddExplosionForce (explosionForce, transform.position, explosionRadius);

However, the objects hit by the explosion seem to constantly floating over my map eternally.
I watched the Tanks tutorial (video 5 I guess) by Unity because they are covering this topic but I couldn’t figure out my problem.

Have anyone of you experienced the same problem?

Do you have any advice for me?

Thank you very mich in advance.

Okay I figured it out.
My objects were not on the ground but some pixels over it.
This caused my objects to float around after hit by the explosion.