'A biased oppinion'
When you like something and right a report on it your opinion will come through about that subject, the same thing occurs if you dislike something.
:) Hope this helps x
Answer: Solor cycles and tings
The answer is, "the speed of the current is 5 miles per hour."
To calculate the speed of the current,
let's assume speed of current = xmph. Time taken to travel from one pier to another with the current = 100/(20+x)h
But the time taken to travel from one pier to another with the current, which is given is = 4 hours. So, 4=100/(20+x) 80+4x = 100
4x = 20
x = 5 Thus, the speed of the current is 5 miles per hour.
Explanation:
It is given that,
Fundamental frequency, f = 220 Hz
(a) We know that at 0 degrees, the speed of sound in air is 331 m/s.
For open pipe, 
l is the length of pipe
Also,


(b) Let f' is the fundamental frequency of the pipe at 30 degrees and v' is its speed.


v' = 348.71 m/s
So, 

f' = 232.4 Hz
Hence, this is the required solution.