oh, thanks.. i now use this function and it works:
Code:

---

void erdbeere()
{
	NewtonBody *body = newton_addentity(me, 10, NEWTON_CONVEXHULL, onforceandtorque);
	NewtonBodySetVelocity(body, vectorf(0,0,-5));
	c_updatehull(me,0);
	set(my,POLYGON|FLAG2);
	while(my.z>20)
	{
		wait(1);
	}
	NewtonDestroyBody(nworld, body);
	ent_remove(me);
}

---

thanks again for your help