Video Transcript
Infrared cameras form images by
detecting the amount of infrared radiation emitted by different objects. The following picture shows two
infrared images of a cup. The key shows how different
temperatures correspond to different colors. In one of these images, the cup
contains hot water. In the other image, the water has
cooled down and is cold. In which of the images is the water
emitting the most infrared radiation? (A) Image A, (B) image B.
In this question, we are being
asked which cup is emitting more infrared radiation based on its temperature. We can see by looking at the color
of the cups that the yellow one is hotter than the blue one, because we have a scale
that tells us higher temperatures show up as more yellow, whilst lower temperatures
appear more blue.
Let’s recall that the amount of
infrared radiation an object gives off depends on its temperature. An object with a higher temperature
emits more infrared radiation than an object with a lower temperature. Since Image A is of a cup
containing water at a higher temperature, this water will emit more infrared
radiation than the water seen in Image B. Therefore, our final answer is
option (A), image A.
