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1 vote
2 answers
59 views

Euler Rotation Equations and invariance of vectors in different reference frames

Consider two frames, one which is inertial and the other one rotating w.r.t. to the inertial frame. Say there is a rigid body having angular momentum which is same/invariant in both frames. How is it ...
0 votes
1 answer
44 views

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 ...
-1 votes
1 answer
168 views

Apparent velocity of winds

If I run north at 10j m/s and the wind is also blowing north at 2j m/s, then do I feel a wind of 8m/s in my face if the relative velocity of the wind to me is -8j m/s ?
-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 ...
1 vote
1 answer
60 views

Simple classical mechanics problem to compute minimum distance attained between two ships moving with constant velocity

I have been reading the book "A Course in Classical Physics 1 - Mechanics" by Alessandro Bettini. I have reached a problem in the first chapter that I am having trouble with. The problem ...
1 vote
1 answer
3k views

Finding resultant and direction of resultant

In this question- A motorboat is racing towards the north at 25km/h and the water current in that region is 10km/hr in the direction of 60 degrees east of the south. Find the resultant velocity of ...
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 ...
0 votes
3 answers
239 views

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 ...
0 votes
1 answer
95 views

For an airplane moving north from some latitude (say $30^{\circ}N$), why does rotation of the Earth cause an increase in apparent drag?

I'm not able to understand the answer to this example: Example 10 from the Curtis Orbital Mechanics text book : An airplane of mass $70 000\ \mathrm{ kg}$ is traveling due north at latitude $30^\circ$...
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 ...
0 votes
1 answer
111 views

Distance between two airplanes [closed]

I need help with a vector problem where my solution is different from that of my teacher. The translation of the problem reads as follows: An air traffic controller observes two aircraft on his radar ...
1 vote
2 answers
7k views

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 ...
2 votes
3 answers
675 views

I am moving right and rain is falling vertically down.Why should I hold umbrella at an angle?

This is related to relative velocity.I get that, from my moving frame of reference rain is making an angle.But still... it doesn't make sense to hold umbrella at an angle when rain is falling ...
0 votes
0 answers
3k views

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 ...
1 vote
1 answer
40 views

Why do we say the resultant vector as the relative motion in this case?

If a car A moves with acceleration $2m/s^2 $due east and car B moves $1m/s^2 $due north. What would be the acceleration of car B with respect to car A. Now , for this. The solution in my textbook is ...

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