Vector Velocities: Help Needed for Test Tomorrow

[xCanx]

I really need help as I have a test tomorrow and am having trouble with these problems.

I have attached the questions and my work in the picture below.

http://img79.imageshack.us/img79/9886/scan0001po5.th.gif

Both answers are wrong. Can somebody tell me what I am doing wrong and if my diagrams are drawn correctly. Any help would be appreciated. Thank you.

 

[alphysicist]

Hi xCanx,

I really need help as I have a test tomorrow and am having trouble with these problems.

I have attached the questions and my work in the picture below.

http://img79.imageshack.us/img79/9886/scan0001po5.th.gif

Both answers are wrong. Can somebody tell me what I am doing wrong and if my diagrams are drawn correctly. Any help would be appreciated. Thank you.

The speed you found for the boat (4.27 m/s) would be the speed if the boat was pointed directly across the stream. In that case, the current would drag the boat downstream, so it does not match the problem.

In this case, they want the boat to actually move straight across the water. So the boat must be pointed somewhat upstream, so as to cancel out the effect of the water. Since some of its velocity is being used to cancel the water, the total velocity should be less than 4m/s.

Does this help? What do you get?

 

[baba89]

Dear student,

I understand your concern and the urgency for help with vector velocities. It is important to approach these problems with a clear understanding of the concepts and principles involved. From the attached image, it seems like you have attempted the questions but your answers are incorrect.

Firstly, it is important to note that velocity is a vector quantity, meaning it has both magnitude and direction. In order to correctly solve vector velocity problems, you need to consider both the magnitude and direction of the vectors involved. It seems like you have correctly identified the direction of the vectors in your diagrams, but the magnitude may be incorrect.

I would recommend reviewing the principles of vector addition and subtraction, as well as the use of trigonometric functions to determine the magnitude of a vector. It may also be helpful to practice with simpler vector problems to build your understanding and confidence.

In addition, it is always helpful to seek assistance from your teacher or classmates if you are struggling with a particular topic. They can provide you with further explanations and examples to help you better understand the concept.

I wish you all the best for your test tomorrow. With proper understanding and practice, I am confident that you will be able to solve vector velocity problems successfully. Remember to approach them with a clear understanding of the concepts and take your time to carefully analyze and solve each problem. Good luck!