Final answer:
Emily measured the amount of time it took for each candle to burn. This statement is identified as the measurement of elapsed time, which is a fundamental concept in Physics.
Step-by-step explanation:
The statement 'Emily measured the amount of time it took for each candle to burn' is concerned with the measurement of elapsed time, which is a key concept in Physics.
This type of measurement often involves considering the changes that occur as time passes, such as the burning of a candle, which can be related to topics like thermodynamics and rate of reaction.
In Physics, understanding the principles behind measuring time intervals is important, as highlighted by various experiments and observations, for instance, the use of flash lamps on a moving train to understand relative motion and the measurement of light arrival to determine the timing of events.
Consider the example from the provided text, 'Now suppose we use this method to measure the time interval between two flashes of light produced by flash lamps on a moving train,' which shows how the measurement of time is fundamental in understanding concepts such as relative motion in Physics.
Moreover, the same principle is used in various real-world applications, such as timing the duration that a cookie recipe lasts, performing experiments with candles, or understanding the properties of materials like wood as they burn.