How Do You Calculate a Boat's Path Across a River with a Current?

  • Thread starter Thread starter eb22
  • Start date Start date
  • Tags Tags
    Boat Current
AI Thread Summary
To calculate a boat's path across a river with a current, first determine the boat's speed relative to the starting point by using vector addition of the boat's speed in still water and the current's speed. The time taken to cross the river can be calculated by dividing the river's width by the component of the boat's speed directed across the river. Additionally, the downstream distance can be found by calculating how far the current carries the boat during the crossing time. A right triangle can be used to visualize the relationship between the boat's speed and the current. Understanding these components is crucial for solving the problem effectively.
eb22
Messages
1
Reaction score
0
1. A boat has a speed of 1.50 ms-1 in still water. It is used to cross a river 500 m wide along which there is a strong current of speed 0.900 ms-1. The boat is directed straight towards the opposite bank but the water current carries it downstream. Calculate:
(A) the boat's speed relative to the starting point
(B) the time taken to reach the bank on the other side
(C) the distance the boat is carried downstream from the point of departure at one bank to the point of arrival on the opposite bank



2. Literally don't know where to start. I feel like I have been staring at problems from my lectures and don't know how to relate this to any of them.



3. I drew out a diagram and can see that it makes a right triangle, but it feels like I need more information and I don't know how to find it. Also, I can't figure out how to the speed of the boat to the speed of the current.
 
Physics news on Phys.org
show your work. don't just say you've done it, then maybe we can see where you are going wrong.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...

Similar threads

Back
Top