Average Rate of Movement seems like a different way to try to say “average Speed”
Avg Speed = (Total Distance) / (Total Time)
1st) Bill walks with the elevator until he Catches up with the People
Bill’s Effective Speed = (3 + 3) = 6 ft/sec ———as the moving walkways helps push him along and extra 3 ft/sec faster
The Gap Distance that Bill must Catch Up and Close = 120 ft
The group of people are moving with the walkway at 3 ft/sec in the Same Direction
Time = Gap Distance / Relative Speed = 120 / (6 - 3) = 40 seconds
In these 40 seconds, Bill travels: 6 * 40 = 240 feet
The 2nd Part is where Bill moves with the moving walkway and stands still.
60 feet remains
Bill’s Speed at this point = Walkway Speed of 3 ft/sec
Time = 60 / 3 = 20 seconds
Average Speed = (Total Distance of 300 ft) / (Total Time of 40 seconds + 20 seconds)
Avg Speed = 300 / 60 =
5 ft/sec
-E- is the Correct Answer
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