A man swims 320 m against the water current in 4 minutes. In still water, he is able to swim with a speed 5 times that of the current. Using vectors, calculate the speed of the current, in m/min.
Answers
Let the speed of the current is x m/min and speed of the man is y.
The man swims 320 m against the water current in 4 minutes.
i.e., y - x = 320/4 = 80 m/min .....(1)
again, The man is able to swim with a speed 5 times that of current.
i.e., y = 5x..........(2)
from equation (1) and (2),
5x - x = 80 m/min
or, 4x = 80 m/min
or, x = 20m/min
hence, the speed of the current is 20m/min.
Answer:
Speed of the current = 20 m/min
Explanation:
Let the speed of the current be x.
In still water the man swims with a speed that is five times the speed of the current.
Speed of man in still water = 5x
When he swims against the current he swims at a speed = 5x - x = 4x
Given the distance and the speed we can get time as :
Time = Distance/speed
Distance = 320 meters
Speed = 4x
Time = 4 minutes
320/4x = 4
320 = 4x × 4
16x = 320
x = 320/16
x = 20 meters per minute
This is the speed of the current.
Speed of current = 20m/min