Question

In order to measure the period of a single pendulum using a stop clock, a student repeated the experiment for $10$ times and noted down the time period for each experiment as $5.1, 5.0, 4.9, 4.9, 5.1, 5.0, 4.9, 5.1, 5.0, 4.9\, s$ . The correct way of expressing the result for the period is

• A. 4.99 s
• B. 5.0 s
• C. 5.00s
• D. 4.9 s

Answer 1

Answer: (B)

5.0 s

Answer 2

Mean $=\frac{\Sigma x_{i} f_{i}}{10}=\frac{(4.9 \times 4)+(5.0 \times 3)+(5.1 \times 3)}{10}$
$=4.99 \,s$
Which can be round off to $5.0\, s$ correct to two significant figures.