2. a. You take a red brick, heat it with a blowtorch (so you can feel that its h
ID: 2040814 • Letter: 2
Question
2. a. You take a red brick, heat it with a blowtorch (so you can feel that its hot) and put it in a dark room. Is it emitting light? What wavelength regime (ultraviolet, visible, infrared)? b. You turn on the light in the room, Is the brick emitting more or less light than before? Why do you think the brick appears red to the eye-is this from the emitted light ? c. You put the brick in the refrigerator and cool it down. Then you put it back in the dark room. Is it emitting more or less light than when it was hot? Is it emitting any light? d. Now consider a block of glass. Do you think that glass is transparent to all wavelengths of light? You heat up the glass with a blowtorch. Does it emit light?Explanation / Answer
The color of the objects that we see is mainly due to the way those objects interact with light and ultimately reflect or transmit it to our eyes. The color of an object is not actually within the object itself. Rather the color is the part of the visible spectrum of light that reaches our eyes after reflection or transmit. When visible light strikes an object and a specific frequency becomes absorbed, that frequency of light will never make it to our eyes.
So in case of the brick in a dark room it won’t emit any light as the brick don’t have the capacity to emit light by its own so we won’t be able to see the brick in a dark room.
If the brick is placed in a lighted room then the brick will appear red as the blue part of the visible light spectrum is absorbed by the brick and the reflected part is predominately red so the brick appear red.
In the case of a glass brick if we heat the glass as the heat increases the emitting radiation frequency decreases it’s called black body radiation. So if we heat the glass brick it will eventually be red hot as the frequency is transmitted is in the red area of light spectrum.
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