Geologists use two sensors to measure the speed of seismic P waves through rock. The expected speed of the waves is 6000 m/s.
In their current set-up, the sensors are 1500 m apart and the timer has a resolution of 0.010 s. The geologists replace this timer with a portable timer that has a resolution of 0.030 s.
Treat the timer resolution as the uncertainty in the measured travel time, and assume the distance measurements are accurate.
Calculate the minimum sensor separation needed with the portable timer so that the percentage uncertainty in the travel time is no greater than in the current set-up.
112 exam-style questions on Edexcel GCSE Physics 4.1 Wave properties, covering 4.1.1 Waves transfer energy and information, 4.1.2 Frequency, wavelength, amplitude, period and wavefronts, 4.1.3 Longitudinal and transverse waves, 4.1.4 The wave speed equations, 4.1.5 Measuring wave velocity, and 4.1.6 Calculating depth or distance from waves. Each one has a worked solution and a mark scheme showing where the marks go.