Question

Tommy let a marble roll down the hill outside his house. He released it from the same place 4 times and recorded the following times. Express the average time using the correct number of significant digits.

A) 4.00 seconds
B) 4.0 seconds
C) 4 seconds
D) 4.000 seconds

Answer 1

To find the average time with correct significant digits, one should add all the times and divide by the number of trials, preserving the precision. For four trials each at 4.00 seconds, the average time is 4.00 seconds (Option A).

Step-by-step explanation:

To calculate the average time using the correct number of significant digits, we will add up all the recorded times and then divide by the number of trials. It is crucial that we respect the recorded precision of the times, as this will inform us of how many significant figures our final answer should have.

If Tommy recorded times of 4.00 seconds for each trial (focusing on the most precise measurement), and he released the marble four times, then:

Average time = Total time / Number of trials = 16.00s / 4 = 4.00 seconds

Since each individual time was measured to the hundredth of a second, and there were no fluctuations in time, we must express the average time to the same level of precision. Therefore, the correct answer is 4.00 seconds (Option A).