ASVAB (Armed Services Vocational Aptitude Battery)Mathematics Knowledge (MK)Hard
A reconnaissance drone flies at an altitude of 1,500 feet. If its current speed is 180 miles per hour, what is the drone's speed in feet per second? (1 mile = 5,280 feet, 1 hour = 3,600 seconds)
- A300 fps
- B396 fps
- C264 fps
- D132 fps
Show answer & explanationAnswer & explanation
Correct answer: C. 264 fps
To convert 180 miles per hour to feet per second: (180 miles / 1 hour) * (5280 feet / 1 mile) * (1 hour / 3600 seconds). The 'miles' and 'hours' units cancel out, leaving 'feet per second'. Calculation: (180 * 5280) / 3600 = 950400 / 3600 = 264 feet per second.
Why the other options are wrong
- A. Possible error in one of the conversion factors (e.g., using 60 for hours to seconds).
- B. Significant calculation or conversion error.
- D. Error in conversion factor or calculation.
Multi-Unit Conversion (Speed)
Converting speed from one set of units (e.g., mph) to another (e.g., fps) requires sequential multiplication by appropriate conversion factors, ensuring units cancel out correctly.
- Use conversion factors as fractions (e.g., 5280 ft/1 mile).
- Arrange factors so unwanted units cancel out (numerator vs. denominator).
- Multiply all numerators and divide by all denominators.
Memory trick: Miles 'M'ust 'M'ultiply, 'H'ours 'H'ave 'H'uge 'D'ivision.