All Questions
Tagged with relative-motion kinematics
172
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How to calculate the relative speed when three bodies are involved? [closed]
Two trains A and B start from a station and move in parallel tracks with velocities 40 kmph and 60 kmph respectively. A man sitting in train A. watches a lady who walks inside the train B at a speed ...
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2
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116
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How Fast Must a Man Run to See Rain Falling horizontally?
The fact that tan 90° is undefined indicates a key issue in the problem.
Does this mean it is impossible to observe rain falling at 90 degree?
When rain is observed to be falling at 90° with the y-...
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43
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The stupidest question ever on relative kinematics and angular velocity [duplicate]
I am scratching my head on a very basic formula whose meaning escapes my intuition.
On basically all texts of mechanics the following result is derived:
Suppose that a rigid body is moving with ...
- 130
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75
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How does relative motion work for an extended object?
I have this conceptual doubt which might be flawed very badly but I don't understand this particular thing. For example, if one end of a stick is moving with velocity $v_1$ and the other with $v_2$, ...
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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 ...
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The distance problem [closed]
Say a car has to move from Point A to Point B on the surface of the earth. The car starts from rest at Point A at time $t=0s$ reaches point B at time $t=10s$ with a constant velocity of $1000 m/s$. ...
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75
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Wording of Relative Velocity problems [closed]
I've been doing some relative velocity problems. The three main types I do are to do with cars, boats/rivers and planes/crosswind.
I'm fine with cars as the wording is pretty straightforward - it is ...
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53
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To find the displacement of a rolling body
When calculating the displacement of a rolling body do we just calculate the displacement due to Vcom in a particular time t or additionally need to consider also the displacement that may be produced ...
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Why is throwing a bullet by hands not effective as using a gun? [duplicate]
The bullet when fired applies equal and opposite force to the Gun, (Newton's 3rd law)
Thus to keep the gun stable we apply some force which should be equal to the force applied by the bullet.
If we ...
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27
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Unifrom circular motion along the horizontal plane
Imagine that a person is walking with a constant velocity along the horizontal plane and
turns the fan on the filing into a circular motion. Then, after sometime the fan will achieve a constant ...
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2
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2
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429
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Is all change movement? [closed]
Is there a change in the universe that cannot be reduced to movement? One counter-example should be enough. :)
Heat is a type of change that was once thought to be qualitative, but is now realized to ...
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Velocity of Separation and Relative Velocity
I have some problems in understanding a concept, which has been used in the problem in the picture:
I don't understand what are we actually using to solve this question. Are we using relative ...
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5
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Do released objects take the direction and speed of their parent frame's velocity, or just the parent frame's speed component?
Context: I'm working on a space game. I noticed that an unpowered object fired from a strafing spaceship appeared, as the released object moved, to curve in the direction the ship was strafing. This ...
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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 ...
- 121
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Is the relative velocity between these two particles increasing or decreasing? [closed]
The displacement time equations of two particles are:
$$s_1 = 2t-4t^2$$
$$s_2 = -2t + 4t^2$$
By differentiating we can find $v_1,v_2$. Subtracting them gives: $v_1-v_2 = 4-16t$
Clearly, this ...
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