A student stands 60m from a vertical cliff face on a calm day. She claps her hands once and uses a stopwatch that resolves 0.01s to record the time between the clap and the echo returning from the cliff. She repeats the procedure twice: once at dawn when the air temperature is 0∘C and once in mid-afternoon when the temperature is 30∘C. The table below gives measured values of sound speed in dry air at several temperatures.
Temperature T(∘C) 0 10 20 30
Speed v(m/s) 331 337 343 349
(a) Using the table, state the speed of sound the student should use for each of her two trials.
(b) For each temperature, calculate the time interval between the clap and the returning echo. Show your reasoning clearly.
(c) Determine the numerical difference between the two echo times, and comment on whether this difference is large enough to be resolved with the student’s stopwatch.
(d) Describe two real-world factors, other than temperature, that could influence the accuracy of the student’s determination of sound speed in this experiment.