Place a rail, and put a minecart on that rail. Then place a shulker/bring a shulker next to the minecart. It will go into it. Then place a wall 5 blocks tall next to the shulker minecart. Place a gravity block above the shulker minecart by tapping/clicking on the wall of blocks. When it falls, it will pass right through the shulker & onto the ground. If you do that again, the gravity block will float above the shulker.