Additional Info

• ID Code: f2-27
• Purpose: To illustrate an interesting brainteaser about bouyancy
• Description: Each pan of a balance holds a beaker of water, filled to the same level. In one beaker, a ping-pong ball floats, tethered by a string to the bottom of the beaker. In the other beaker, a steel ball of equal volume hangs suspended from an outside support. The balance can be clamped to hold it level. Invite students to predict what will happen when the clamp is removed: Will the balance remain level, will the side with the ping-pong ball go down (that side is heaver), or will the side with the steel ball go down (that side is heavier)? Encourage students to explain their reasoning and discuss amongst themselves.
• Availability: Available