ARCHIMEDES' PRINCIPLE
EQUIPMENT
Plummet
Plummet Cup
Overflow Can
Spring Scale (in Newtons)
Collecting
Beaker
NARRATIVE
A body submerged in water loses weight equal to that of
its own volume of water. This demonstration kit includes an Overflow Beaker, a Collecting
Beaker, a Scale, and a Cup and Plummet that has the same volume as the inside of the cup.
Show that the Plummet just fits inside the Cup demonstrating that these have the same volume. Fill the Overflow Beaker with water until it overflows. Discard the overflow. Hang the Cup from the scale and hang the Plummet from the Cup.
Observe the weight of the empty Cup and Plummet. Lower the assembly into the Overflow Beaker until the Plummet is completely submerged, simultaneously catching the displaced liquid in the Collecting Beaker. Note the loss of weight is caused by submersion. While keeping the Plummet submerged, pour the collected water into the Cup. Observe that the added weight of the displaced liquid just equals the loss in weight due to submersion.