Answer:
- butterfly
- 1 second in 68 ft, or 2 4/15 ft/s
Step-by-step explanation:
Speed is the ratio of distance to time. Speeds can be compared by comparing the times for the same distance, or by comparing the distances for the same time. A faster speed means more distance is covered in less time.
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Here, we observe that 68 feet is a multiple of 34 feet, so it is easiest to compare the speeds of the insects by comparing their times for the same distance.
butterfly: 68 ft in 5 seconds
dragonfly: 2×34 ft in 2×3 seconds, or 68 ft in 6 seconds
The butterfly covers the same distance in less time, so it can fly faster.
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Since our comparison of speeds is made using travel times, we can say the answer to "how much faster" is "1 second less over a distance of 68 feet."
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<em>Additional comment</em>
You may be expected to figure the speeds in units of feet per second. You do that by dividing feet by seconds.
butterfly: 68 ft/(5 s) = 13.6 ft/s
dragonfly: 34 ft/(3 s) = 11 1/3 ft/s
The difference in speeds is ...
(13 3/5) -(11 1/3) = 2 4/15 . . . ft/s
The butterfly's speed is 2 4/15 ft/s faster than the dragonfly's speed.
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You see time comparisons in human foot races, often with differences measured in milliseconds. Almost never are speeds compared in terms of feet (or meters) per second.
