Prototype 1

Prototype 1 did not work well and lost 36.9°C in 20 minutes. It was a glass cup with paper towel covering it to block air and used aluminium foil as a lid to reflect the heat back. Did this not work well because the aluminium foil absorbed a lot of heat.

 

Prototype 2

Prototype 2 worked better than prototype 1. This time we used a styrofoam cup instead of a glass cup and that made a significant change because a styrofoam cup has a lot less thermal conductivity. We also put a paper towel underneath the aluminium foil to reduce thermal conductivity and on the bottom. This wasn’t a good idea because now the aluminium foil won’t be reflecting the heat and we also had no reason to cover the bottom of cup.

 

Prototype 3 / Final

Materials: 1 styrofoam cup, 1 paper cup,1 plastic lid, 10×1.5 inch and 2×2 inch aluminum foil, 1 cotton balls, 1×1 and 0.5×0.5 tape, 1 layer of paint.

We know heat is energy and it transfers from hot to cold. It transfers by three ways: conduction, convection, and radiation. Conduction is the flow of heat through physical contact. The particles in the object bump into the other particles in another object to transfer heat. Convection is the transfer of heat through motion of a fluid. Hot fluids rise up because it is less dense than colder fluids. Radiation is the transfer of heat through electromagnetic waves. The electromagnetic waves have energy and it is absorbed by the object that is getting hit. We used a styrofoam cup to hold the water because it has a very low thermal conductivity. That means it is a poor conductor of energy so it won’t transfer the heat as fast. We then put a paper cup to cover to styrofoam cup to prevent new cold air from transferring after the air that inside the cup gets warm. We used a plastic lid because it is also a poor heat conductor and used cotton balls to cover the holes on the lid. We put aluminium foil around the inside of the paper cup and underneath the plastic lid to reflect the thermal radiation that is coming off of the boiling water. Then we used tape to keep everything held together. We could have made it better by using a smaller paper cup. This helps because then there would be less air inside the cup which means the heat transfers to the air. We also could have used more cotton balls or used something else to block air better because the cotton ball let in some air.