vector word problem (about transportation)

[sylvia]

Two riverboat landings are directly across from each other. A boat traveling at a speed of 12 mph is attempting to cross directly from one landing to the other. If the current of the river has a speed of 4mph, at what angle should the skipper head?

I get confused on the diagram and how to set up the problem...... Can Anyone help!!????

 

[wjm11]

Two riverboat landings are directly across from each other. A boat traveling at a speed of 12 mph is attempting to cross directly from one landing to the other. If the current of the river has a speed of 4mph, at what angle should the skipper head?

Try reading/studying these examples and see if they help you:

http://www.physicsclassroom.com/class/vectors/u3l1f.cfm

http://www.algebra.com/algebra/homework/word/travel/Travel_Word_Problems.faq.question.320331.html

http://www.physicsclassroom.com/class/vectors/u3l1g.cfm

http://www.cramster.com/answers-oct...eed-835m-crossing-river-fr_1566420.aspx?rec=0

(I have not joined/checked the last site.)

Hope that helps.

 

[soroban]

Hello, sylvia!

Two riverboat landings are directly across from each other.
A boat traveling at a speed of 12 mph is attempting to cross directly from one landing to the other.
If the current of the river has a speed of 4mph, at what angle should the skipper head?

    |                           |
    |               C           |
    |               *           |
    |     12    *   ↓           |
    |       *       ↓ 4         |
    |   * @         ↓           |
  A *   *   *   *   * B         |
    |                           |
    |                           |

The boat wants to go from \(\displaystyle A\) to \(\displaystyle B\).
But the current moves from \(\displaystyle C\) to \(\displaystyle B.\)
To compensate, the boat must go from \(\displaystyle A\) to \(\displaystyle C.\)

We are asked for \(\displaystyle \theta\), the angle at \(\displaystyle A.\)

Any ideas?