At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
@ganeshie8 @nincompoop @dan815
Your sketch is accurate. You are after
Yes, I know this way to solve it but I was seeking a different way to do it. Would you mind checking it?
Sure. Go ahead
Ok, since the river is 0.5 Km wide and the swimmer can swim with a speed of 2 km/h it will take 0.5/2 = 0.25 hours for him to reach the other side. The swimmer will actually aim along AO but due to the river flow he will reach at B. While reaching B he has travelled a horizontal distance of 1 * 0.25 = 0.25 Km due to river flow. |dw:1437535731457:dw|
Now AB/OB = tan
He swims at 2 km/hr, but if he is travelling along segment OA, he is not making progress across the river at 2 km/hr, but rather at 2cos
Yes but isn't he still making 2km/h across the vertical direction?
Nope. He is travelling at 2 km/hr at 30 degrees CCW to the vertical
So he is making progress across the river at 2cos 30 = 1.73 km/hr.
Yes, that makes sense now.
Super. Good question.
what do you understand about the question
not the given, but the question it wants you to solve for.
I already tried it according to my understanding above, turns out i was taking 2 km/h as vertical velocity of swimmer but it is actually his velocity across line Ao
You are doing the same mistake I guess. I thought this way too but actually the swimmer will have 2 km/h velocity along AO and a velocity of 2 cos 30 along the vertical direction.
I am showing you what happens if he just swam. I am not telling you that is the answer
He is not swimming vertically. He is swimming along the 30 degree line.
It should be like this
I treat them as forces and use the component method. I am not sure if 30 deg is an estimation or the actual angle.
here are extra readings to do http://faculty.wwu.edu/vawter/PhysicsNet/Topics/Vectors/VectorAdditionSteps.html http://physics.bu.edu/%7Eduffy/semester1/c3_vadd_comp.html
Thanks all for the help.