All Questions
21
questions
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1
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44
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The locus of the velocity vectors of a boat navigating in the sea under the presence of a very strong wind?
I already asked a question very similar to this one here and I think the solution would not work when the boat navigates in the sea when a very strong wind blows. That is I am trying to find the ...
- 159
3
votes
3
answers
515
views
Relative velocity related to acceleration
Let's say we have a car moving on the horizontal ground with a velocity of $10 \hat{i} \frac{m}{s}$. A person inside throws a ball vertically upward with a velocity of $3 \hat{j} \frac{m}{s}$. Now I ...
- 169
0
votes
3
answers
239
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A question about relative motion and how to make sense of it
So, here is the question:
Assuming the 2D Cartesian system and the basis vectors $\hat{i}$ and $\hat{j}$, we have two cars A and B located at (0,6) and (-30,0) respectively. Car A starts moving with a ...
- 169
1
vote
1
answer
124
views
Velocity of an object with respect to the same object
I know that velocity of an object with respect to the same object is a null vector but I'm not able to get a grasp of it.
Whatever I had thought till now is that if I'm sitting in a train (which may ...
- 882
1
vote
2
answers
7k
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What will be the minimum drift possible when a boat crosses a river? [closed]
Imagine a boat with a constant speed $v$ that has to cross a river of width $d$. Let the river flow with a constant velocity $u$. I want to know the angle at which the boat should sail in order to ...
0
votes
0
answers
3k
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On a rainy day, a man is running on a hilly terrain in such a way that he is always finding the rain drops hitting him vertically
It is assumed that rainfall is uniform in the whole terrain from O to E(figure attached) When the man was at rest on stretch OA, he found the rainfall at an angle of $30^o $ with the vertical.
What ...
- 309
-1
votes
1
answer
52
views
Why is direction of train like this for car?
This is an image of a train and a car. T is the train moving towards - $x$ axis and C is the car moving towards $+ y$axis.
So, my teacher made a resultant velocity with $-5\hat i$ and $-20\hat j$. ...
- 725
0
votes
1
answer
38
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Direction of $V_RM$ confusion
So ,please read both the questions . They have similar originate questions that I am facing difficult in.
Let us say rain is falling downwards with v = -5j and a man is moving with a velocity of 2i in ...
- 725
-2
votes
1
answer
69
views
Problem regarding relative velocity [closed]
Train A moves north with speed 54km/h. What is the velocity of a monkey running on roof of a train A against its motion (with velocity of 18km/h with respect to A)as observed by a man standing on ...
- 47
1
vote
0
answers
80
views
Vector addition of drone affected by wind
I've been struggling with this calculation for around a week and am starting to question whether or not it's even possible.
What I want to do is find the bearing and speed a drone will need to fly at ...
- 11
1
vote
1
answer
100
views
Signs in relative vector addition
So I know the formula for relative vector addition is
$$w = \frac{v-u}{1-\frac{uv}{c^2}}.$$
How do I chose when to use this formula or its inverse transformation for solving vector addition problems ...
- 33
-1
votes
2
answers
4k
views
What does speed of an object relative to water mean?
A swimmer swims with the velocity 1.25 m/s "relative to water". He has to swim across the river which is 150 meters wide. If his direction of velocity is perpendicular to the stream, he is taken away ...
- 203
0
votes
1
answer
605
views
Is this Question correct? Newtonian Motion - Relative Motion of Rain
There is a question in a textbook which states:
"A cyclist is riding north at 12km/h when it starts to rain. The rain appears to be falling towards her at an angle of 10 degrees relative to the ...
- 57
1
vote
1
answer
611
views
How does one solve a 2D relative velocity problem given 3 angles and 1 magnitude?
Most of it is the title. To be a bit more clear, I am asking about a problem involving two traveling objects. The question gives you the angle of motion of both objects relative to the earth, and the ...
- 175
3
votes
1
answer
4k
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Calculating relative velocity in three dimensional space
Given two points $\mathcal{A}$ and $\mathcal{B}$ in $\mathbb{R^3}$ whose position and velocity vectors are, respectively:
$$\mathbf{r_A}=\begin{pmatrix}r_{A_{x}}\\r_{A_{y}}\\r_{A_{z}}\end{pmatrix}$$
$$...
- 133