Easy Cool Ice Box Preparation
For this activity, the students make a net in math class to use for their Easy Cool Ice Box. They then add materials to the net to help minimize heat transfer into the box where their ice cube is stored.
Before beginning the activity, students need to be introduced to the concepts of conductors and insulators. Conductors allow energy (heat or electrical energy) to travel easily along them. Insulators do not allow energy to travel easily along them. So, for example, aluminum foil (a metal, thus a conductor) will transfer heat energy easily, while newspaper (an insulator) will not allow heat energy to transfer easily.
You can decide the amount of time you want the students to test their ice boxes, but keep in mind that 5 - 10 minutes will be too little time, and more than 1 hour will be too much. I have found that 30 minutes works pretty well, but that ensures that you will probably have to test 2 or more designs over multiple class periods. Students can work on another assignment will their ice boxes are in use. Students will surely note that certain things will be different about each group’s testing situations, the biggest being that the ice cubes will not be the exact same size, so that will affect the amount of the ice that melts from their cube. This is a good time to discuss variables, and how not keeping that variable exactly the same may indeed affect their outcome, but it can be very difficult to control things such as the size of the ice cubes.
Provide a materials table for the students to choose the materials to line their boxes. Materials may include:
newspaper
aluminum foil
cotton balls
paper
different types of cloth material
waxed paper
plastic wrap
etc...
You really can put a lot of things at the materials station, and the students will try many of them -
string, rubber bands, plastic baggies, anything that you have lying around in your science lab or kitchen. Let their imaginations go crazy!
Other materials you will need for this lab are:
For each group of four to six students:
10 - mL graduated cylinder
50 - mL graduated cylinder
plastic cup
For each group of two/three students:
one ice cube
one plastic bag
Make sure that you allow at least one, if not more, times for the students to redesign their ice box if their ice melts more than they want. This is a major step of the engineering design process and is how professional engineers make sure their prototypes are the best possible. We want students to understand that changing their design does not equate failure. It is how they learn and make great products! One problem that may occur is that after the first trial the cardboard of their nets make become compromised, especially any design they may have made on them with markers or crayons, etc.... This is why it is important that they each make a net in math class, so there will be at least two in each group.