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Ch.1 - Chemical Tools: Experimentation & Measurement
McMurry - Chemistry 8th Edition
McMurry8th EditionChemistryISBN: 9781292336145Not the one you use?Change textbook
All textbooksMcMurry 8th EditionCh.1 - Chemical Tools: Experimentation & MeasurementProblem 96
Chapter 1, Problem 96

The world record for the women's outdoor 20,000-meter run, set in 2000 by Tegla Loroupe, is 1:05:26.6 (seconds are given to the nearest tenth). What was her average speed, expressed in miles per hour with the correct number of significant figures? (Assume that the race distance is accurate to 5 significant figures)

Verified step by step guidance
1
Convert the time from hours, minutes, and seconds to total hours. Start by converting the seconds to minutes and then the total minutes to hours.
Convert the distance from meters to miles. Use the conversion factor: 1 mile = 1609.34 meters.
Calculate the average speed using the formula: \( \text{Average Speed} = \frac{\text{Distance}}{\text{Time}} \).
Ensure that the final answer is expressed in miles per hour.
Round the final result to the correct number of significant figures, considering the given data.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Unit Conversion

Unit conversion is the process of converting a quantity expressed in one set of units to another. In this question, we need to convert the distance of 20,000 meters to miles and the time of 1:05:26.6 to hours. Understanding how to perform these conversions accurately is essential for calculating the average speed in the desired units.
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01:56
Conversion Factors

Average Speed Calculation

Average speed is defined as the total distance traveled divided by the total time taken. To find Tegla Loroupe's average speed, we will use the formula: average speed = distance/time. This concept is fundamental in physics and helps quantify how fast an object is moving over a specific distance.
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Average Rate Calculation Example

Significant Figures

Significant figures are the digits in a number that contribute to its precision. When performing calculations, especially in scientific contexts, it is important to report results with the correct number of significant figures based on the precision of the measurements involved. In this case, the race distance is accurate to 5 significant figures, which will influence how we express the final average speed.
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Significant Figures Example
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