Why do we measure the time for 20 oscillations instead of one?

Question:

You want to measure the period of oscillation t. Yet, you were asked to first measure the time for 20 oscillations, and then find the time for one oscillation. What is the reason we do this? Why not simply measure the time for one oscillation directly?

Answer:

The main reason we measure the time for 20 oscillations instead of one is to increase the accuracy and reduce uncertainty in our measurement. The method of measuring the time for 20 oscillations and then finding the time for one oscillation is commonly used in physics experiments involving oscillatory motion, such as pendulum experiments.

Understanding the Principle:

Accuracy is crucial in scientific measurements as it ensures that the results are reliable and consistent. When dealing with oscillations, especially those of a pendulum, the ability to measure the period with high precision is essential for making accurate calculations and predictions.

The Uncertainty Factor:

How accurate do you think the measurement would be if you simply let a pendulum swing once, beginning a stopwatch when you let go, and stopping it when the oscillation was complete? The biggest uncertainty, in my opinion, is your ability to start and stop the stopwatch precisely at the beginning and conclusion of the oscillation. In other words, if you repeated the identical action, let's say five times, you would receive five different results for the pendulum's oscillation period. Naturally, you could always average the numbers, but the range of the results would show how unpredictable the oscillation period was.

The uncertainty in directly measuring the time for one oscillation lies in the human error involved in starting and stopping the stopwatch accurately. Even minor variations in reaction time can lead to significant discrepancies in the measured period. By measuring the time for multiple oscillations and then calculating the average time for one oscillation, we can minimize the impact of these uncertainties and obtain a more reliable result.

Therefore, by measuring the time for 20 oscillations and then determining the time for one oscillation, we improve the accuracy of our measurements and reduce the effects of human error and uncertainty in the experiment. This approach allows us to obtain more precise values for the oscillation period and ensures the validity of our scientific findings.

For further information on oscillation and its measurement methods, you can explore additional resources to enhance your understanding and application of these principles in scientific experiments.