A group of swimmers is resting in the sun on an off-shore raft?
May 27, 2009 by Rafting and Kayaking Tips
Filed under More Rafting Answers
Can you answer strawberry’s question about Rafting?:
A group of swimmers is resting in the sun on an off-shore raft. They estimate that 3.0 m separates a trough and an adjacent crest of surface waves on the lake. They count 14 crests that pass by the raft in 20 s. How fast are the waves moving?
Used Raft
A group of swimmers is resting in the sun on an off-shore raft. They estimate that 3.0 m separates a trough and an adjacent crest of surface waves on the lake. They count 14 crests that pass by the raft in 20 s. How fast are the waves moving?
Used Raft
Rafting Feedback: speed = distance / time
………….= 3*2*14 m / 20s……………….(3*2 = wavelength)
………… = 4.2 m/s
Rafting Feedback: wavelength is from crest to crest so your wavelength is 6. 14 crests pass by at 6m apart thats a total of 84m. 84m in 20 seconds is 4.2m/s
check with calc i did it in my head
Rafting Feedback: Do you mean 3m between each wave’s peak and trough?
Then 14*6 = 84 metres in 20 seconds
= 4.2 m/s.
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