Purpose: To demonstrate Archimedes' principle.

A. Submerged body. Fill the spouted beaker with water until it is on the verge of overflowing through the spout. Place an empty beaker under the spout. Show the class that the cylinder just fits inside the can. Hang the can from the spring balance, and hang the solid cylinder by the short chain from the bottom of the can. Have the class note the weight of the can and cylinder (the balance is calibrated in Newtons). Holding the top of the balance, lower the cylinder into the water until it is submerged and water stops running out of the spout. Note the apparent weight. Pour water from the small beaker into the can; notice that (1) it exactly fills the can, and (2) the scale reads the same as it did with the cylinder outside the water.

B. Floating body. Arrange the water level and small empty beaker as initially in part A. Hang the can only from the balance and note its weight. Hold the balance by its top and lower the can into the water until it floats. Note that the apparent weight goes to zero. Raise the can out of the water, pour the water from the small beaker into the can, and note that the combined weight of water and can is twice the can's weight.

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