 triangle.position = CGPoint(x: scene.size.width * 0.75,
                             y: scene.size.height * 0.50)
 
+let l = SKSpriteNode(imageNamed: "L")
+l.name = "shape"
+l.position = CGPoint(x: scene.size.width * 0.5, y: scene.size.height * 0.75)
+l.physicsBody = SKPhysicsBody(texture: l.texture!, size: l.size)
+
+scene.addChild(l)
 scene.addChild(square)
 scene.addChild(circle)
 scene.addChild(triangle)

scene.physicsWorld.gravity = CGVector(dx: 0, dy: 0)
scene.physicsBody = SKPhysicsBody(edgeLoopFromRect: scene.frame)
sceneView.showsFPS = true
sceneView.presentScene(scene)

XCPlaygroundPage.currentPage.liveView = sceneView

    sand.physicsBody = SKPhysicsBody(circleOfRadius: sand.size.width/2)
    sand.name = "sand"
    scene.addChild(sand)
    sand.physicsBody!.restitution = 1.0
    sand.physicsBody!.density = 20.0
}

func shake() {
    scene.enumerateChildNodesWithName("sand") { node, _ in
        node.physicsBody!.applyImpulse(CGVector(dx: 0, dy: random(min: 20, max: 40)))
    }
}

delay(seconds: 2.0) {
