Solve Vectors Problem: Get from A to B Faster

[BilloRani2012]

In a race you are asked to get from A to a particular point B directly opposite
on the other side of a wide river of width 1km as fast as you can. You have a motor
boat that can manage a speed of 5m/s, but the river has a current of 2.5m/s. You
estimate that you can run at 2.5 m/s.

a) In your practice run you head out pointing your boat at an angle of 90 degrees to
the bank. How long does it take you to get from point A to point B?

b) Disgusted by your time you decide to reduce your running time to zero. In what
direction should you point your motor boat? How long will it now take you to get
from point A to point B? Did you make a better time?v

 

[zhermes]

What aspect of the problem are you having issues with?
Is there something in particular that doesn't make sense?

What are the relevant equations and concepts to this problem?
How do you think you can get started?
Generally starting by drawing a picture of the situation helps.

 

[falcon2616]

I am also having trouble with this questions similar, it is in part b.
I just don't know how to find the angle the boat needs to head off at to end up at point B.

 

[Norfonz]

Draw the vectors, use vector properties, trig, etc.

Also, this shouldn't be in advanced physics.

 

[BilloRani2012]

i drew the vectors. so would it be

(2.5-2.5sin30)i + (5-2.5cos30)j

= 1.25i + 2.83j

so, t = distance(m) / vertical velocity
t = 1000 / 2.83
t= 353.3 seconds

is that right?

 

[Thornberry]

by any chance are you doing math1050 at UQ lol

 

[inshalla]

maybe :D