For this activity, groups will try to make a boat out of materials not typically used for making something that will float. The boat must float and carry a load of pennies for a specified time in a tub of water.
Plastic tub or foil roasting pan (1 per group)
Water (1 gallon per group)
100 US Pennies (per group, 1983 or newer, older pennies weigh more)
Paper (plain 20lb letter size is fine)
Stapler with staples
Stopwatch or timing device (one per group)
Organize the class into groups (two or three in a group) if they aren't already. You will need an even number of groups for this activity.
Explain to each group that they are to make a boat from the “unlikely material”.
Each group should fill their plastic tub with enough water so that the boat will float.
Once the boat is floating with 100 pennies in it, start timing.
Keep track of how many seconds the boat was able to float with the pennies, up to five minutes.
Don't let the boat touch the sides of the tub. If the boat touches the sides, the group must put the boat back in the middle of the tub and start timing again.
Once the groups have all had a chance to try this a few times (even if they never succeed in floating 100 pennies for 5 minutes), pair each group with another group (this is why you need an even number of groups).
Have the new groups create a new boat. The new boat must hold 200 pennies for as long as possible.
Give the new groups some time to create a new boat and time how long it can hold 200 pennies.
Did your first group succeed?
What was the design process like? How much time did you spend discussing what to try? How much time making boats and testing them?
Did your second (larger) group succeed?
How was the design process in the larger group different?
Did you use any of the same ideas from the smaller groups?
Did you come up with new ideas in the larger groups?
In the first part, you had a target time. In the second, there was no target time (just “as long as possible”). Did that affect how you went about designing your boat?
What works great in your class that you could share with others?
What is a struggle in your class that someone else may be able to help with?
How does your approach to the task change when the goal is a finite amount versus “as much as possible”?
float_the_pennies.txt · Last modified: 2021/06/04 10:50 (external edit)