All Questions
Tagged with relative-motion vectors
47
questions
1
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1
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611
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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
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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
0
votes
1
answer
288
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Why the point right below the center of a rolling ball on the ball has zero instantaneous velocity [duplicate]
Suppose there is a snooker ball rolling on a table. The velocity of the center of the ball is Rω and its direction is horizontally right. I don't understand why the point right below the center on the ...
- 23
1
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1
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3k
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Problem on relative motion involving wind speed .Finding the real velocity of wind?
Here is the question
For a person running west at 7km/hr wind appears to blow from north-west .But when he walks towards west at 3km/hr the wind appears to blow from the north. What is the true ...
- 31
0
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1
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1k
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Relative Motion of Child and Boat [closed]
A boat is traveling upstream at $11~\text{km/h}$ with respect to the water of a river. The water is flowing at $7.0~\text{km/h}$ with respect to the ground. What are the
(a) magnitude
(b) ...
- 249
1
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1
answer
113
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Speed with wind resistance
This is probably a basic question, but it has been a while since I did anything like this.
If a boat is sailing forward at speed $x$ and the direction of the wind, with magnitude $y$, is either equal, ...
- 11
1
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1
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3k
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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 ...
- 715
3
votes
3
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878
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What is the relative velocity of this plane relative to the helicopter? [closed]
There is a plane moving 100 m/s due east relative to the ground without vertical motion. There is a helicopter facing north moving straight up at 20 m/s. From the perspective of the helicopter, is the ...
user57358
1
vote
1
answer
4k
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Kinematics simple question [closed]
Question: In order to protect himself from the rain, a person is standing holding an umbrella at right angle to the horizontal surface. The rain is falling at 10m/s when the velocity of the wind is ...
- 1,582
4
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1
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32k
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What does relative to something mean?
I just started learning about vector components and relative motion. I don't understand what relative to something means. I looked online but none of the explanations are helpful.
If someone could ...
- 155
0
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2
answers
1k
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Relative motion. Setting course of closest approach
Let $r_{P/Q}$ be the position vector of $\overrightarrow P$ relative to vector $\overrightarrow Q$ and $v_{P/Q}$ the velocity vector of $\overrightarrow P$ relative to $\overrightarrow Q$.
Suppose $|...
- 238
0
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1
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Relative motion and how to calculate magnitude and velocity of objects relative to different given objects [closed]
A canoe has a velocity of 0.550m/s southeast relative to the earth. The canoe is on a river that is flowing at 0.540m/s east relative to the earth.
Alright so I attempted many different things an ...
- 49
0
votes
1
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2k
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Finding an equation to solve for the velocity of a swimmer crossing a river [closed]
Where $\theta=45^\circ$, $d_1=200\:\mathrm{m}$, and $d_2=150\:\mathrm{m}$.
I do not know how to combine the following equations:
$$\begin{align}
t&=\frac{d_1}{v_s\cos(45^\circ)}\\
t&=\frac{d_2}...
- 49
0
votes
2
answers
679
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Relative velocity of boat
I am trying to understand fully the following question:
A boat is traveling west at 100m/s and is partially helped by a strong wind blowing at 20m/s 30 degrees north of west. What speed could the ...
- 316
3
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2
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4k
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I don't understand the idea of perpendicular vectors being independent of each other?
So problem 71-75 is about vectors. The problem says:
A river has a current flowing with a velocity of 2.0 meters per second due east. A boat is 75 meters from the north riverbank. It travels at 3.0 ...
- 189