To determine how many hours it would take for a falcon to fly 52,800 feet at a speed of 68 mph, we can start by converting the distance from feet to miles, since the speed is given in miles per hour (mph).
1 mile is equal to 5280 feet. Therefore, to convert 52,800 feet to miles, you would do the following calculation:
\[ \text{Distance in miles} = \frac{52,800 \text{ feet}}{5280 \text{ feet/mile}} = 10 \text{ miles} \]
Now, we can find out how many hours it takes to cover that distance at 68 mph using the formula:
\[ \text{Time (hours)} = \frac{\text{Distance (miles)}}{\text{Speed (miles/hour)}} \]
Substituting in the values:
\[ \text{Time} = \frac{10 \text{ miles}}{68 \text{ miles/hour}} \approx 0.1471 \text{ hours} \]
However, to answer your original question about what unit to convert from feet, the correct answer is miles because we are working with mph.
So, the value that corresponds to your answer is:
Option #1: miles