public void setLinearVelocity(Vector3f vec) {
        rBody.setLinearVelocity(Converter.convert(vec, tempVec));
        rBody.activate();
    }
Sets the linear velocity of this PhysicsRigidBody
@param vec the linear velocity of this PhysicsRigidBody
jme3-jbullet/src/main/java/com/jme3/bullet/objects/PhysicsRigidBody.java