Final answer:
It would take approximately 80 nanoseconds for a light signal to make a round trip in a 12-meter lab classroom, utilizing the defined speed of light in a vacuum of 299,792,458 meters per second.
Step-by-step explanation:
The question asks how much time it would take for a light signal to make a round trip from one end of a 12-meter lab classroom to the other and back, given the speed of light. To find the time, we can use the fact that light travels at a speed of approximately 299,792,458 meters per second in a vacuum, as defined since 1983. The round-trip distance is twice the length of the classroom, so it is 24 meters in total. Thus, we calculate the time (t) taken for light to travel this distance using the formula:
t = distance/speed
t = 24 meters / 299,792,458 meters per second
Calculating this gives us a time of approximately 80 nanoseconds for the light signal to travel the round trip in the lab classroom, assuming that the light travels in a vacuum and there are no obstructions or delays due to the medium.