Science Buddies: "Ask an Expert"

Hi! I am doing a science fair project. My project is that so when your coffee is cold, you can turn a dial or flip a switch to make the coffee hotter. I got an electrical kit and I want to attach a heating coil or a wire to the electrical source and wrap it around the mug so the mug will heat up. What type of wire will work as a heating coil? Will this project work?


Justin

Hi Justin,
You'll need to purchase special 'resistive' wire to heat up your mug. There is a product commonly known as "heater tape' thats used to wrap around and heat pipes. You probably shouldn't be wiring up anything yourself and plugging it into the wall. Creating heat in normal electrical transmission is considered a bad thing, wasted power, so regular copper wire is operated in a regime that it does not heat up too much.

Maybe a better though related project would be to measure how much energy you need to put into coffee/water, to heat it up. You could heat up a submersible resistive element in a cup of water and measure the temperature change. Knowing how much power you put into the resistor you can predict the waters temperature change. You can do this all theoretically first.

Another idea would be to investigate the phase change from ice to water, this link will give some info on both subjects...
http://hyperphysics.phy-astr.gsu.edu/hb ... se.html#c1