For this challenge were asked to design and create three prototypes for thermoses (within the budget of $3.00 to see who could lose the least amount of heat after 45 minutes in the final testing day.

Procedure:

Results for 3 prototypes:

Prototype #1:

Prototype #1 Temperature vs time graph & Picture:

Prototype #2:

Prototype #2 Temperature vs time graph & Picture:

Prototype #3:

Prototype #3 Temperature vs time graph & Picture:

Final Test:

For my final thermos test, I used my first prototype, which was made with a styrofoam cup, aluminum foil on the outside, paper towel under the aluminum foil, and an aluminum foil lid. The results from this final test were that my thermos lost 24.8ºC in 45 minutes. I would have liked to use my second prototype because it had less heat loss, but it was $1.61 over our budget, so I didn’t use it.

For this design, I used a styrofoam cup, because it has a lower thermal conductivity, which contributed to less heat loss. I then wrapped the cup with a paper towel as insulation, and then I used aluminum foil around the paper towel and for the lid. When I made this prototype I didn’t completely know why I had put the aluminum foil around the outside, but I later learned that it would help if I had the aluminum foil around the inside. What did help was having an aluminum lid because it caused the heat from the water to bounce back, and not escape from the cup.