Heat Transfer Application The best way to see whether you understand something is to apply it in new situations, so here are a few: In the following questions, there are illustrations that represent examples of heat transfer. Your job is to determine which method of heat transfer applies to each image, classifying the heat transfer as conduction, radiation, or convection. Of course, some illustrations can fit into more than one category, so see if you can determine all possibilities.

Conduction, Convection, Radiation? Lizard sunning on a rock Some conduction and mostly radiation: There might be some conducted heat when the lizard first lies on the rock, but after that the heat she gets is radiated heat from the sun.    Radiated heat from the sun is causing the lizard to warm up, so clearly this is an example of radiation.

Conduction, Convection, Radiation? All three! Under an electric blanket Conduction. The electric blanket is in direct contact with “Honey”, so molecules transfer heat via collisions. Radiation. Any hot object radiates infrared waves. This is not the primary means of heat transfer, though. Convection. The radiated heat rises & the cooler air sinks setting up a convection current.

Conduction, Convection, Radiation? Radiation and some conduction Baby chicks under a lamp There is direct contact between the light bulb and the air molecules surrounding the bulb, and those air molecules come in contact with the chicks. But air is not a good conductor of heat, so this is not the primary form of heat transfer taking place.   Radiation is the main method of heat transfer. Infrared radiation from the light bulb warms the chicks.

Conduction, Convection, Radiation? Fish tank with a heater in the water The heater causes the water around it to get hotter. The hot molecules move faster, collide more and start moving apart. The hotter water becomes less dense and rises above the denser, cooler water while the cooler water sinks, buoying the warmer water up. This rising and sinking because of temperature & density differences sets up a convection current.