Design, Build, and Test a Prototype of the Cold Pack In this task, you’ll design and build a prototype of the cold pack. The cold pack will allow the user to start a chemical reaction that absorbs energy. The reaction involves mixing powders from two compartments with water.

Estimated time to complete: 2 hours

You will need these materials:
safety goggles
1 toilet paper tube or a small rectangular box (depends on cold pack compartment shape from Task 2)
scrap cardboard of different thicknesses, such as cereal boxes, tagboard, and shipping boxes
scrap paper
scissors
glue
tape
thread or string
paper clips
plastic produce bag or similar
½-cup measuring cup
1-teaspoon measuring spoon
4 teaspoons baking soda
water

Part A
Identify the problem that the cold pack must address.

Part B
Criteria are the specific goals of the design. List at least two criteria for the design based on the question, What do you want it to do? Keep in mind the design of the cup and what you learned from observing the endothermic chemical reaction.
Part C
Constraints are the limits that we place on a design. Time, materials, or money may be in short supply. Some designs may also be limited by how the product gets used. List at least one constraint on the cold pack design.