Weight of Submerged Block

Used to demonstrate the concept of buoyancy. A block is submerged in a tank of water, which is placed on a scale. The block can hang from a spring scale. You can separately measure the weight of the tank, the weight of the tank+block, the weight of the block alone, the apparent weight of the block when suspended in water, the weight of the tank+block when the block is attached the spring scale. It had better all add up!