Pour 1 cup of tap water into four glass jars or large drinking glasses. Add 2 tbsp. salt to two of the containers and stir until dissolved. Gather four styrofoam cups that are smaller than the jar mouths and fill each half-full of water. Add 1 tbsp. salt to two of the cups and stir until dissolved. Place all four cups in the freezer for several hours until the water turns to solid ice. Remove ice from each cup. Place one salted sample and one unsalted sample into the two jars of regular tap water. Put the remaining samples in the saltwater jars. Observe and measure to determine how far each iceberg is submerged below the surface. Discuss water density and the difference in icebergs created from freshwater or saltwater, and the composition of the water body in which they travel.
Create four icebergs by freezing water and 1 tbsp. of salt in four 1-gallon freezer bags stored upright. Gather four clear plastic storage tubs, deep and wide enough to hold one of the icebergs. Fill the tubs with tap water and place a heat lamp directly over the second tub. Add one tray of ice cubes to the third tub and 1 cup of salt to the final tub, stirring until dissolved. Add one iceberg to each tub and use a stopwatch to determine how long it takes each berg to melt completely. Use the data gathered from observations and time records to conclude what locations and seasons icebergs pose the greatest risk to passing ships.
Create a large iceberg by filling a plastic trash bag with water and storing in a deep freezer for several hours until solidified. Place a deep plastic storage tub in a 66-qt. underbed storage tub. Remove the iceberg from the plastic and set in the deep tub. Fill the deep tub to the brim with tap water. Hypothesize whether the water level will decrease, stay at the same height, or spill over the edge as the iceberg melts. Observe the tub every 10 minutes until the iceberg melts. Repeat the experiment outside to see if results differ.
Set a 1-by-3-inch wood beam across a bathtub. Make an 18-inch adjustable loop from copper wire by placing the wire around the beam; twist the wires together. Place a small block of ice on top of the wood and slide underneath the wire. Pull the wire tight around the ice and twist the loose end of the wire around a 1-gallon jug fillled with water, so it is suspended in the tub directly below the beam. Wait 10 minutes or until the wire completely passes through the ice block and record observations of what happens to an iceberg under pressure.