Hey thanks for the help: I have another question:
A swimmer is capable of swimming 0.30 m/s in still water.
(a) If she aims her body directly across a 75 m-wide river whose current is 0.55 m/s, how far downstream (from a point opposite her starting point) will she land?
(b) How long will it take her to reach the other side?
timetogetacross=75m/.30m/s
Now use that time to figure how far downstream with the water velocity.
I'm not sure I quite understand what you mean
^ That was me btw
To answer these questions, we need to consider the relative motion of the swimmer and the river current.
(a) To find out how far downstream the swimmer will land, we need to calculate the time it takes for the swimmer to cross the river. We can do this by dividing the width of the river by the swimmer's resultant velocity:
Resultant Velocity = Swim Speed + River Current
= 0.30 m/s + 0.55 m/s
= 0.85 m/s
Time = Distance / Resultant Velocity
= 75 m / 0.85 m/s
≈ 88.24 s
Therefore, it will take approximately 88.24 seconds for the swimmer to cross the river. At this time, the swimmer will have been carried downstream due to the current. So, to find out the distance downstream, we multiply the current velocity by the time:
Distance Downstream = River Current * Time
= 0.55 m/s * 88.24 s
≈ 48.523 meters
Therefore, the swimmer will land approximately 48.523 meters downstream from the point opposite her starting point.
(b) To calculate the time it takes for the swimmer to reach the other side of the river, we need to consider the distance she needs to travel in the river's direction. This is equal to the width of the river:
Time = Distance / Swim Speed
= 75 m / 0.30 m/s
= 250 seconds
Therefore, it will take the swimmer approximately 250 seconds to reach the other side of the river.