Final answer:
To calculate the mass of a mystery box with a stopwatch, one could be performing a physics experiment using gravitational acceleration. Proper measurement techniques include accounting for reaction time and averaging multiple trials to account for uncertainties. The total mass would be calculated and reported with the appropriate significant figures.
Step-by-step explanation:
To calculate the mass of a mystery box using a stopwatch, we must be conducting an experiment that relates mass to time, such as using gravitational acceleration in free-fall experiments. First, one would need to determine the reaction time on the stopwatch, as it can impact the measurement accuracy.
By starting and stopping the stopwatch as quickly as possible, this reaction time can be estimated. To account for uncertainties in the measurement, such as the stopwatch's inherent uncertainty of ±0.05 s, multiple measurements should be taken and then averaged.
Once reaction time and uncertainties are considered, the mass of the mystery box can be calculated using the formula v=at=gt, where v is the final velocity, a (or g) is the acceleration due to gravity (9.80 m/s²), and t is the time measured with the stopwatch.
This could be part of an experiment where the box is dropped from a specific height, and the time it takes to hit the ground is recorded. The total mass would be reported with the proper significant figures, taking into account the measured values and unit conversions.
If the context involves measuring a chemical's mass, the student would weigh the empty container, add the chemical, weigh again, and subtract the empty container's mass from the total.