Crossing a river?

  • Thread starter megamax48
  • Start date
  • #1
1
0

Homework Statement



A hunter wishes to cross a river that is 1.5 km
wide and that flows with a speed of 6.6 km/h.
The hunter uses a small powerboat that moves
at a maximum speed of 14 km/h with respect
to the water.
What is the time necessary for crossing if
the boat goes directly across the river? An-
swer in units of min.

Homework Equations


?


The Attempt at a Solution


I dont even know where to start.
 

Answers and Replies

  • #2
drizzle
Gold Member
366
57
welcome to PF megamax48 :smile:

you need to find the net velocity acting on the boat, calculate the angle with respect to the boat speed vector [theta=tan[SUP]-1[/SUP] vy/vx=tan-1 vriver/vboat], get the distance using the angle and the river’s width, finally calculate the time using the calculated distance and the net velocity. you better draw this so you can understand it well

ps. don't forget to convert the units
 
Last edited:

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