1. **Problem:** Convert 20 miles per hour (mi/hr) to inches per second (in/s). 2. **Formula and conversion factors:** - 1 mile = 5280 feet - 1 foot = 12 inches - 1 hour = 3600 seconds 3. **Step-by-step conversion:** \[20 \frac{\text{mi}}{\text{hr}} = 20 \times \frac{5280 \text{ ft}}{1 \text{ mi}} = 105600 \frac{\text{ft}}{\text{hr}}\] 4. Convert feet to inches: \[105600 \frac{\text{ft}}{\text{hr}} = 105600 \times 12 \frac{\text{in}}{\text{ft}} = 1267200 \frac{\text{in}}{\text{hr}}\] 5. Convert hours to seconds: \[1267200 \frac{\text{in}}{\text{hr}} = 1267200 \times \frac{1 \text{ hr}}{3600 \text{ s}} = \frac{1267200}{3600} \frac{\text{in}}{\text{s}}\] 6. Simplify the fraction: \[= \cancel{\frac{1267200}{3600}} = 352 \frac{\text{in}}{\text{s}}\] 7. **Answer:** 20 miles per hour is equal to 352 inches per second.