River Boat Question That's Throwing Me Off

In summary, a man rows a boat across a river that flows due north with a speed of 2.90 m/s. His velocity relative to the water is 5.50 m/s and his landing point is due east relative to his initial position. The river is 1000 m wide. To determine his speed relative to the earth, we first need to consider the man's direction of travel. Since his landing point is due east, we can deduce that he is traveling at an angle relative to the eastern direction. Additionally, since his landing point is due east of his initial position, we can also determine that he aims his boat at an angle relative to the eastern direction. To cross the river, the man takes 181
  • #1
Ben B.
6
0

Homework Statement


A river flows due north with a speed of 2.90 m/s. A man rows a boat and reaches the opposite shore right across its initial position; his velocity relative to the water is 5.50m/s. His landing point is due east relative to its initial location. The river is 1000 m wide.
a). What is his speed relative to the earth?
b.) At what angle does he travel relative to the eastern direction?
c.) At what angle does he aim the boat relative to the eastern direction?
d.) How much time is required to cross the river?
e.) How far north of his starting point will he reach the opposite bank?


Homework Equations


Vbg2=Vbr2+Vrg2

t=ΔX/Vbr

Distance=Speedavg x t

The Attempt at a Solution

[/B]I had a similar problem before this one but this specifies that he reached the opposite shore right across from his initial position which is throwing me off.
a.) 5.52+2.92=√38.66 -> 6.22 m/s
b.) Wasn't sure how to even do this for this question
c.) ^ ditto
d.) t=1000/5.5= 181.82 s
e.) Distance= 2.9 x 181.52 s = 527.28 m

Unfortunately those were all wrong :(
 
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  • #2
Ben B. said:
a.) 5.52+2.92=√38.66 -> 6.22 m/s
Using pythagorean's theorem to add vectors only works if they are perpendicular. So if the man pointed his boat directly east (which is perpendicular to north) then your answer for the speed would be correct.
However the man does not point his boat directly east.
The man points his boat in such a way that "his landing point is due east relative to his initial position."
So what does this mean about part (e)? And what about part (b)? (Do those two parts first, they require no calculations.)
Then do part (c) then do part (a) then do part (d).
 

1. How does a river boat navigate through different water levels?

The river boat uses a system of locks and dams to navigate through different water levels. Locks are like elevators for boats, raising or lowering them to the level of the water on either side of a dam.

2. How does a river boat stay on course without a steering wheel?

A river boat typically uses a rudder, which is a flat piece of wood or metal attached to the back of the boat. The rudder is controlled by a steering wheel or a tiller, which is a long handle used to turn the rudder and steer the boat.

3. How does a river boat handle strong currents and rapids?

A river boat is designed to be able to handle strong currents and rapids. The boat's hull is shaped in a way to deflect the force of the water, and the boat's engines can be used to maneuver through rough waters.

4. How does a river boat generate power for its engines?

Most river boats use diesel engines to generate power. The engines are fueled by diesel, which is a type of fuel made from crude oil. Some river boats also use hydraulics or electric motors to power their engines.

5. How does a river boat communicate with other boats and shore stations?

River boats typically use a combination of radios and signal flags to communicate with other boats and shore stations. They may also use lights, horns, and other visual signals to communicate important information, such as their location or intention to pass another boat.

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