A simple pendulum is known to have a period, T = 1.55 s. Student A uses their smartphone stopwatch app to measure the total time for 5 oscillations and divides that by 5 to report an average period of T = 1.25 s. Student B uses the same technique but goes old school and whips out his grandpa’s analog stopwatch to come up with an average of T = 1.5 s. What is the most probable source of error that explains the different results?

Given that,

Time period of simple pendulum is 1.55 s.

Time period of simple pendulum for A student =1.25 s

Time period of simple pendulum for B student =1.5 s

We know that

The accuracy is defined as how close a measurement is to a known value .

The result of student of A is 1.25 s. It is more precise because it has more significant figure than student B's result of 1.6 s.

But the measurement made by student B's is much closer the known value of 1.55 s.

Hence, The most probable source of error is the result of student A.

the force on the thing and the distance the force moves the thing

we need to know the time interval during which the force acts. impulse of force = momentum change