- #1

Giu1iano

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Mod note: Moved from a technical section, so missing the homework template.

Hi, I'm struggling to understand this problem. I would normal just wait for class but I'm away traveling for work.

The question is as follows.

A man has a boat that can travel at 15.0 m/s relative to the water. He starts out from the south shore of a river and plans to cross so that he lands directly across the river from his starting point. The river has a velocity of 8.00 m/s East relative to the shore.

a) at what angle should he point his boat?

b) what will be his velocity relative to the shore?

c) if the river is 300 meters wide, how long will it take him to cross?

Answers: a) [N32°W] b) 12.7 m/s [N] c) 23.6s

For a) I used Tan=8/15, Tan=28° or [N28°W] (which is wrong)

b) I used a^2+b^2=c^2 to solve the resultant Lane. 8^2+15^2=289, √289=17 or 17 m/s[N] (which is wrong)

c) I used time=displacement/velocity, t=300m/17m/s, t=17.6s.

I missed the lecture for this class because of work, and my teachers notes confuse me. I'd appreciate any help!

Thank you :)

Hi, I'm struggling to understand this problem. I would normal just wait for class but I'm away traveling for work.

The question is as follows.

A man has a boat that can travel at 15.0 m/s relative to the water. He starts out from the south shore of a river and plans to cross so that he lands directly across the river from his starting point. The river has a velocity of 8.00 m/s East relative to the shore.

a) at what angle should he point his boat?

b) what will be his velocity relative to the shore?

c) if the river is 300 meters wide, how long will it take him to cross?

Answers: a) [N32°W] b) 12.7 m/s [N] c) 23.6s

For a) I used Tan=8/15, Tan=28° or [N28°W] (which is wrong)

b) I used a^2+b^2=c^2 to solve the resultant Lane. 8^2+15^2=289, √289=17 or 17 m/s[N] (which is wrong)

c) I used time=displacement/velocity, t=300m/17m/s, t=17.6s.

I missed the lecture for this class because of work, and my teachers notes confuse me. I'd appreciate any help!

Thank you :)

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