Which of the following is the correct conversion of 45 miles per hour to kilometers per hour (km/h)? (Use 1 mile = 1.609 km)

• A. 60.0 km/h
• B. 72.4 km/h
• C. 45.0 km/h
• D. 28.0 km/h

Answer: (B)

Verified step by step guidance

1. Identify the given quantity and the units to convert: 45 miles per hour (mi/h) needs to be converted to kilometers per hour (km/h).
2. Recall the conversion factor between miles and kilometers: 1 mile = 1.609 kilometers.
3. Set up the conversion by multiplying the given speed by the conversion factor to cancel out miles and introduce kilometers: \$45 \ \text{mi/h} \times \frac{1.609 \ \text{km}}{1 \ \text{mi}}$.
4. Perform the multiplication of the numerical values (without calculating the final number here) to find the speed in km/h: \$45 \times 1.609$ km/h.
5. Interpret the result as the speed in kilometers per hour, which will be the correct converted value.