Physics Kinematics of a swimmer

AI Thread Summary
To determine the velocity of the current affecting a swimmer crossing a 200 m wide river, the swimmer is swept downstream 480 m in 6 minutes and 40 seconds. The correct calculation involves breaking the motion into components, focusing on the downstream displacement. The current's velocity is found by dividing the downstream distance (480 m) by the total time (400 seconds), resulting in a current speed of 1.2 m/s. The swimmer's direct crossing distance of 200 m is not relevant to this specific calculation of current velocity. Understanding the problem in terms of components is crucial for accurate results.
Hafsaaa
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Hello I need help on the following problem:
A swimmer heading directly across a river 200 m wide reaches the opposite bank in 6 min and 40 sec she is swept downstream 480 meters, what is the velocity of the current?


Homework Statement


v = ? ; t = 6 min 40 seconds
Dx = 200
Dy= 480


Homework Equations


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The Attempt at a Solution



well I basicaly used the formula for velocity ( which is V= delta d/ delta t)
so I plugged in the numbers and converted time into 400 seconds and divided by 680 and ended up with .588
the answer is given, but its the work that matters
MY solution: .588 m/s
auctual solution: 1.2 m/s

can someone tell me where I went wrong?
 
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Break the motion into an x and y components. We'll say the swimmer undergoes a displacement of 480 meters in the +x direction. The time it takes for this to happen is 6 minutes and 40 seconds (400 seconds). So 480/400 = 1.2 m/s. Remember, the key to solving this is thinking about the problem in components, one where the swimmer swims at his/her speed (which doesn't even apply in this problem) and one component in which water is propelling the swimmer.
 
so the 200m is ignored?
 
Hafsaaa said:
so the 200m is ignored?
Yes.

p.s. Welcome to Physics Forums!
 
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