Colliding between sprite or child of group and other group

[andiua]

Hello. I`ve just start to learned game dev with Phaser.

Read a lot topics here and saw documentation, but I don`t know what to do

I`m trying to colliding between bombs and the ground.

Ground is a group creating from JSON 

function update() {
	bombFires();
	game.physics.arcade.collide(bombFire, floors);
}
function bombFires(){
	if(bombCount > 0 && spaceKey.downDuration(1)){
		bombCount--;
		bombText.setText('Bomb ' + bombCount + ' x');	
		bombFire = game.add.sprite(cyclist.body.x + 20, cyclist.body.y + 70, 'bombFire');
		bombFire.anchor.set(0.5);
		bombFire.animations.add('bombFire');
		bombFire.animations.play('bombFire',20, true);
		game.physics.enable(bombFire, Phaser.Physics.ARCADE);
		bombFire.body.velocity.set(320, 0);
		bombFire.body.gravity.y = gravitation;
	}
}

in this case one bomb always on floor but when I pressed again spasekey old bomb fall and new is on the floor.

Also I`ve tried to do this with group, but result is the same 

function bombFires(){
	if(bombCount > 0 && spaceKey.downDuration(1)){
		bombFire = game.add.group();
		bombFire.enableBody = true;
		game.physics.enable(bombFire, Phaser.Physics.ARCADE);
		bombFire.create(cyclist.body.x + 20, cyclist.body.y + 70, 'bombFire');
		bombsFire = bombFire.getFirstExists(true);

		if(bombsFire){
			game.physics.enable(bombsFire, Phaser.Physics.ARCADE);
			bombsFire.body.gravity.y = gravitation;
			bombsFire.body.velocity.x =320;
			bombsFire.animations.add('bombFire');
			bombsFire.animations.play('bombFire',20, true);
			// game.physics.arcade.collide(bombsFire, floors);
		}
    }
}

 Also I tried forEach on update() and in function bombFires() and addChild to my hero. But nothing help. 

bombFire.forEach(function(){
            game.physics.arcade.collide(bombFire, floors);
            console.log(game.physics.arcade.collide(bombsFire, floors))
        }, this);

 

Can anyone tell me what I do wrong? I`ve no ideas already :(