Hey Cool Kid’s Science person… See if you can cut an ice cube in half without it being cut in half!
Time: 10 minutes set-up and approximately 1-2 hours observing.
- ice cube
- a piece of thin wire (or fishing line)
- a heavy object such as a gallon of water in a plastic bottle with a handle
- surface that can get wet
- a washcloth or sponge to absorb any melting ice
- a thin piece of scrap-wood about the width of an ice cube 1 or 2 inches wide.
- take about a foot and a half of wire and loop it around the handle of the water jug and twist the ends to make a loop
- position two chairs (see picture) next to each other to support the piece of wood to hold the ice cube
- place an ice cube on top of a folded washcloth and place that on top of the wooden support
- Hang the loop of wire over the ice cube so the full weight of the water jug is applying pressure to the ice cube
Observations and Questions:
- What did you observe?
- What do you think is happening?
- How long did it take for the wire to cut through the ice cube?
- How did the wire cut through the ice cube?
- What happened to the ice cube after the wire passed through?
Pressure lowers the freezing point of water. This is caused regelation. The weights cause the wire to increase the pressure on the ice where the wire meets the ice. This pressure melts the ice allowing the wire to slice through slowly. This is the same principle in ice skating where the sharp blade of the ice skate puts tremendous pressure on a small area of ice thus melting the ice briefly and causing the skate to be very slippery over the water film on the ice.
- Try using heavier or lighter weights.
- Try using thicker or thinner wire.