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During a thunderstorm, a frightened child is soothed by learning to estimate the distance to a lightning strike by counting the time between seeing the lightning and hearing the thunder (Fig. P2.25). The speed vs of sound in air depends on the air temperature, but assume the value is 343 m/s. The
a. A child sees the lightning and then counts to eight slowly before hearing the thunder. Assume the light travel time is negligible. Estimate the distance to the lightning strike.
b. Using your estimate in part (a), find the light travel time. Is it fair to neglect the light travel time?
c. Think about how time was measured in this problem. Is it fair to neglect the difference between the speed of sound in cold air (vs at 0°C = 331.4 m/s) and the speed of sound in very warm air (vs at 40°C = 355.4 m/s)?
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Chapter 2 Solutions
Physics for Scientists and Engineers: Foundations and Connections
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