Answer:
Flutter
Explanation:
Flutter is a type of arrhythmia that causes very fast and regular ryth of the atria of about 250 beats per minute.
Arrhythmia can be defined as any sort of irregularity heart rate or rhythm is also called as dysrhythmia.
Arrhythmias can be categorized as heart block, bradycardia, tachycardia, fibrillation, flutter, sick sinus syndrome, and is diagnosed by Electrocardiography.
In Flutter, the heart chambers do get sufficient time to get filled with blood completely prior to next contraction.
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.