Tuesday, May 5, 2015

Figuring out how to cool coffee down fast is, well, cool

Prof. Mirela Fetea’s Physics 242 class was working on a “How to Cool Down Coffee, Tea or Hot Chocolate” project Tuesday at Germanna Community College’s Fredericksburg Area Campus in Spotsylvania.

“There’s a lot of physics in something as simple as making a cup of coffee,” Fetea said. “We all have burned our tongues trying to sip coffee when it’s too hot--waiting to take that first sip can seem like it takes forever.”

She challenged students to apply some of the basic concepts and principles studied this semester in the physics class--heat radiation and absorption, conduction and convection, insulation, etc, to figure out what succession of steps would cool down the liquid the most in three minutes:

Quickly pouring the creamer and sugar in, or pouring them in right before you drink, stirring or shaking the cup, blowing on it.

Fetea explained the winning strategy, which involved continuous movement of an aluminum foil tray full of hot water around a table in the physics lab:

"By moving the tray around they tried to maximize the loss of heat via conduction - transfer of energy by the movement of particles that are in direct contact with each other. The larger the temperature difference between the objects, the quicker the heat transfer is. As soon as the temperature of the table surface increased, they moved the tray to another spot, having a slightly lower temperature--room temperature--and therefore speeding up the heat transfer."

The results:

First place: Nathan Helmly, Ethan Martin, Joseph Medawar, and Vincent Eastman.

Sexond place tie: A team of Ali Hayder, Gabriel Simmons, Michael Hales, and Nathan Richters and a team consisting of Daniel Carder, Kristy D'Alessandro, Donnie Lewis, and Justin Wray.

Third place: Nicholas Short, David Brown, Jake Polend and Matt Perry

Nathan Richters waves a styrofoam cup while team members Gabriel Simmons,
Michael Hales and Ali Hayder blow air onto a tray of hot water
 to cool down a hot liquid during a Germanna Community College physics class.
 Six teams of four students had three minutes to apply some of the concepts
 and principles studied in their University Physics II  class.
(Photo by Robert A. Martin)

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