A student obtains different values each time she measures the period of a pendulum. Which action would best reduce the effect of this random error?
Question 1 Report
A student obtains different values each time she measures the period of a pendulum.
Which action would best reduce the effect of this random error?
Answer Details
Random errors in timing a pendulum arise mainly from human reaction time when starting and stopping the stopwatch. Each individual measurement of the period includes this uncertainty, which is why the student gets different values each time.
The most effective way to reduce this random error is to time a larger number of oscillations and then divide. If you time 20 complete swings instead of one, the reaction-time error (roughly the same fixed amount) is spread over 20 periods rather than one, reducing the percentage error by a factor of 20.
Changing the string length or bob mass alters the period of the pendulum but does nothing to reduce the timing error itself. Measuring the string length more carefully addresses a different source of error (the length measurement), not the timing uncertainty. Only the averaging approach directly targets the random error described in the question.
Download The App On Google Playstore
Everything you need to excel in your exams
