Two students, P and Q, investigate the speed of sound in dry air at a controlled temperature of $20^{\circ }C$.

• Table 1 shows the data obtained by Student P, who used a manual stopwatch and a tape measure over long distances.
• Table 2 shows the data obtained by Student Q, who used a dual-microphone setup connected to a digital storage oscilloscope over laboratory-scale distances.

Table 1: Student P data $\begin{array}{ccccc}Distance\; (m)& Time\; Trial\; 1\; (ms)& Time\; Trial\; 2\; (ms)& Mean\; time\; (ms)& Calculated\; speed\; (m/s)\\ 50& 130& 190& 160& 313\\ 100& 280& 340& 310& 323\\ 150& 420& 480& 450& 333\end{array}$

Table 2: Student Q data $\begin{array}{ccccc}Distance\; (m)& Time\; Trial\; 1\; (ms)& Time\; Trial\; 2\; (ms)& Mean\; time\; (ms)& Calculated\; speed\; (m/s)\\ 0.50& 1.44& 1.48& 1.46& 342\\ 1.00& 2.90& 2.94& 2.92& 342\\ 1.50& 4.35& 4.39& 4.37& 343\\ 2.00& 5.81& 5.85& 5.83& 343\\ 2.50& 7.27& 7.31& 7.29& 343\end{array}$

The accepted true value for the speed of sound under these conditions is $343m/s$.