Crossing Mohawk Bridget: Vector Diagram & Time Needed

  • Thread starter Thread starter pharaoh
  • Start date Start date
AI Thread Summary
Brigget plans to swim across the Mohawk River, which is 200 meters wide, with a swimming speed of 5 m/s and a current of 3 m/s eastbound. To reach her destination on the opposite shore, she must swim at an angle upstream to counteract the current. The net velocity calculated is 4 m/s, leading to a crossing time of 50 seconds. The discussion emphasizes the importance of determining the correct heading relative to the moving water. The solution involves both vector diagramming and understanding the impact of the current on her path.
pharaoh
Messages
47
Reaction score
0
Brigget decides to swim over to Llenorce from the south shore. given she can swim at 5 m/s, the current is 3 m/s eastbound and the width of the mohawk river is 200 meter at that point. in what specific direction must she travel to reach its destination? Diagram the vectors, find her net velocity and detemine the time needed to cross the river?
 
Physics news on Phys.org
Show us your attempt to solve this problem.
 
25-9=16
square root of 16= 4 m/s
average velocity= d/t
200/4= 50 seconds
 
pharaoh said:
25-9=16
square root of 16= 4 m/s
average velocity= d/t
200/4= 50 seconds
That looks good. It appears you have recognized that she must swim somewhat upstream to cancel the effect of the current. Part of the question was the direction she must travel to accomplish this. I assume they meant travel relative to the moving water rather than the shore. Did you find the heading?
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Thread 'Struggle to understand the concept of the question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Vectors Question using Calculus -- Swimmer crossing a River
Replies
30
Views
4K
Adding Vectors to Find Velocity
Replies
16
Views
3K
Stuck on a vector problem: Boating across a river
Replies
11
Views
3K
Velocity Vectors and Navigation Across A River
Replies
4
Views
2K
Which Direction Should a Swimmer Head to Counteract a River Current?
Replies
5
Views
8K
Fisherman's boat Relative motion
Replies
29
Views
3K
River-boat problem (Relative velocity)
Replies
9
Views
7K
Physics Calculating Distance and Direction
Replies
14
Views
3K
Vectors and Kayaking: Solving for Velocity, Time, and Distance
Replies
16
Views
3K
Kinematics in one direction - relative velocity word problem
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top