Convert 55 mph into kilometers per hour (1 mi = 1609 m). a. 88 km/h b. 88.4 km/h c. 89 km/h d. 88.5 km/h e. 88.0 km/h
The correct answer and explanation is:
To convert miles per hour (mph) into kilometers per hour (km/h), use the conversion factor that 1 mile equals 1.609 kilometers. Here’s how to convert:
- Start with the given value:
You are given 55 mph, which is the speed in miles per hour. - Use the conversion factor:
To convert miles to kilometers, multiply by 1.609 (since 1 mile = 1.609 kilometers). 55 mph×1.609=88.495 km/h55 \, \text{mph} \times 1.609 = 88.495 \, \text{km/h} - Round the result:
The result, 88.495 km/h, is rounded to one decimal place to give 88.5 km/h.
Thus, the correct answer is d. 88.5 km/h.
Explanation:
Converting units between different measurement systems, like from miles to kilometers, is a common task in physics and engineering, especially when dealing with speed or distance. To perform such a conversion, it’s essential to know the exact conversion factor. In this case, the factor of 1.609 is derived from the fact that one mile is equal to 1.609 kilometers. By multiplying the number of miles by this factor, you directly convert the measurement to kilometers.
This approach applies whether you’re converting miles to kilometers or any other distance units between different systems. For example, if converting from kilometers per hour to miles per hour, you would use the inverse of the factor, which is approximately 0.6214 (since 1 km ≈ 0.6214 miles). This same process of multiplication can be applied in various contexts to ensure accurate unit conversions.