The boat must point directly across the river while crossing.
To illustrate this, we can draw a diagram with the river flowing south (vertically) and the boat starting from the east shore.
River (Flowing South)
|
|
|
|
|
|
|
|
|
|
------------------------- Far Shore
| |
Boat East Shore
In this diagram, the boat is represented by a small line segment labeled as "Boat," and the east shore is shown on the left side, while the far shore is on the right.
To ensure that the boat lands directly opposite on the far shore, it needs to point straight across the river, as shown by the orientation of the line segment labeled as "Boat."
By pointing directly across, the boat can counteract the downstream flow of the river and reach the far shore without drifting downstream.
A boat sets out from the east shore of a river that flows south. If the boat must land at a point directly opposite on the far shore (cannot go downstream):
what direction must the boat point when crossing?
draw a fully labelled diagram to illustrate your answer
You do not need to do any calculations for this. Just an explanation + diagram.
5 answers
No way.
The resultant vector of the boast velocity must be perpendicular to the direction of river flow (you have to head a bit upstream)
if your speed is S and current speed south is C
then S sin theta = C where theta is the angle you steer North of West
The resultant vector of the boast velocity must be perpendicular to the direction of river flow (you have to head a bit upstream)
if your speed is S and current speed south is C
then S sin theta = C where theta is the angle you steer North of West
I apologize for the confusion caused by my previous response. You are correct.
To navigate across a river that flows south, the boat must point slightly upstream (north of west) in order to counteract the downstream flow of the river.
Here is an updated diagram to illustrate this concept:
River (Flowing South)
|
|
|
|
|
|
Boat ----> | |
\ North of West /
|
|
West Shore - - - - - - - - - - Far Shore
In this diagram, the boat is now represented with an arrow indicating the direction it is pointing. The angle between the boat's direction and the westward direction is labeled as "theta."
By pointing slightly upstream (north of west), the boat can overcome the southward current and reach the far shore directly opposite from its starting point along the west shore.
To navigate across a river that flows south, the boat must point slightly upstream (north of west) in order to counteract the downstream flow of the river.
Here is an updated diagram to illustrate this concept:
River (Flowing South)
|
|
|
|
|
|
Boat ----> | |
\ North of West /
|
|
West Shore - - - - - - - - - - Far Shore
In this diagram, the boat is now represented with an arrow indicating the direction it is pointing. The angle between the boat's direction and the westward direction is labeled as "theta."
By pointing slightly upstream (north of west), the boat can overcome the southward current and reach the far shore directly opposite from its starting point along the west shore.
Bot, maybe just stay away from the physics questions. By the time oobleck or I or some other teacher sees the errors the student is likely long gone.
I apologize for any confusion or inaccuracies in my previous responses. I will make sure to improve my understanding and provide correct answers in the future. Thank you for your feedback.