Questions tagged [relative-motion]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
65 views

Speed of the Earth through universe [closed]

If two negatively charged spheres repel each other in the same way indipendently of Earth velocity does the movement of the Earth around the Sun which is at a short moment in direction with the Milky ...
-5
votes
1answer
62 views

An Evil Vector Problem! [closed]

A person is walking on straight road starting with a velocity $v$, the direction of of air ,observed by him makes an angle $\alpha$ with his is direction of motion. Now during the race, he finds ...
8
votes
2answers
176 views

Why are there so many Doppler Effect formulas?

I was just introduced at my class, a phenomenon, known as the doppler effect, where the observed frequency increases as the source/observer approaches each other, but decreases, if they were moving ...
2
votes
1answer
50 views

Relative velocity from space-time diagram

Consider two frames of reference, with velocities V1 and V2 relative to an initial ground frame. I have made the space-time diagrams for the three frames (Time represented on Y-axis). As far as I ...
1
vote
4answers
56 views

Motion between two particles in a relative manner

Suppose a particle A is travelling in east direction with velocity of x m/s and another particle B is travelling with velocity y m/s in the west direction. Why does the the particle B appears to move ...
-1
votes
2answers
71 views

When formulating and performing experiments for quantum theory do physicists account for us constantly moving through non-zero energy vacuum?

Problem: If we suppose that each smallest possible point in vacuum is a size of Planck length and that point is somehow affecting that particle with spontaneously emerging non-zero energy, then as our ...
1
vote
2answers
46 views

relative acceleration of ball in a train [closed]

A boy is standing in a train with a ball in his hand. The train is having a constant acceleration equal to x m/s^2. While still in train he throws the ball with a constant velocity of 20 m/s at an ...
0
votes
1answer
36 views

Relative motion between two particles

I already know the relation of relative velocity as : Vab=Va-Vb So is there any derivation for this relation or is just how it is defined? Relating to this i am finding some hard time to imagine why ...
0
votes
3answers
60 views

Relative motion with relativity [closed]

In an inertial frame of reference (let's say a car moving with certain constant velocity in which I am sitting) If I observe the motion of another car through my frame of reference i.e.car, will I be ...
0
votes
1answer
67 views

Free fall time after being accelerated [closed]

An elevator car whose floor-to-ceiling distance is equal to $2.7m$ starts ascending with constant acceleration $1.2 m/s^2$; $2.0 s$ after the start a bolt begins falling from the ceiling of the car. ...
1
vote
1answer
86 views

Is there anything in physics that is absolute rather than relative? [closed]

Are there physical quantities that are absolute rather than relative? Things that do not depend on the reference frame? Perhaps I just haven’t learned about them yet. Original (before edit by @G....
0
votes
2answers
48 views

How can we define event to be proper and improper when there is no absolute frame of reference [duplicate]

Suppose in an empty space two rocketships exists with person A and B of same age inside each. Let A move with velocity c/2 away from B and return. They'll find out that B grew older while A didn't ...
1
vote
2answers
79 views

Why can't we take space as universal frame of reference?

Suppose we have a ball filled half with water in space with nothing else around (nothing else in the whole space except the ball) and suddenly it accelerates for time t. obviously, there would be ...
1
vote
2answers
104 views

Relativity and electromagnetic field

I have a question regarding Misner, Charles W.; Thorne, Kip S.; Wheeler, John Archibald (1973), Gravitation ISBN 978-0-7167-0344-0. It is a book about Einstein's theory of gravitation. At the page 79,...
2
votes
1answer
52 views

Why ball fall at same location from where we throw it? [duplicate]

I have a silly question. As we all know earth is rotates at a speed of 460 m per sec. So if I throw a ball in the air for 10 sec than the ball must fall 4600 m away from me but these does not happen ...
0
votes
0answers
18 views

Relative angle and velocity binning around one particle

Let's suppose particle positions and velocities are represented as $P_i = [p_x \; p_y \; p_z]$ and $V_i = [v_x \; v_y \; v_z]$. While, x,y,z represents the 3 components of position and velocity vector ...
1
vote
2answers
53 views

What are the necessary conditions for relative angular velocity to be defined? [closed]

I have certain doubts related to the definition of relative angular velocity .My textbook defines it in the manner given below:- $$\omega_{AB}=\frac{v_{AB}}{r_{AB}}$$ $\omega_{AB}$ is the relative ...
0
votes
1answer
50 views

Can we move without moving? [duplicate]

So here is the question, If I jump and hover over the ground for sometime why don't we move away from the point I jumped from? Because earth is rotating so if I hover long enough we should move from ...
0
votes
2answers
57 views

Meaning of the term speed of light in context of an object of non-zero mass

We know from GR that an object of non-zero mass cannot propagate at light. I have a problem with the term speed of light. Does it mean the relative speed of that object with another object or frame of ...
23
votes
11answers
9k views

If absolute velocity does not exist, how can we say a rocket accelerates in empty space?

If a rocket in space fires its thrusters, it is propelled forwards as per the laws of motion. This can be measured by its position relative to other bodies in the universe. Hypothetically if there ...
0
votes
2answers
75 views

Would close to light speed travel be possible if all atoms in the system were instantly given “forward motion”?

I have heard people say that based on our current understanding and ideas for possible/current technology no person would ever be able to even travel at a solid (70-80%) the speed of light because ...
2
votes
3answers
141 views

Why cannot we determine our own velocity?

I know it would violate the principle of relativity. But have there been serious experimental attempts to contradict that principle? If I am in a moving train without windows and totally sound proof,...
0
votes
0answers
29 views

Question about relative motion by Galilean Transformation?

You are piloting a small airplane in which you want to reach a destination that is 750 km due north of your starting location. Once you are airborne, you find that (due to strong but steady wind) to ...
1
vote
1answer
36 views

Interpretation of directional depenedence in special relativity

I am reading AP French's book, Special Relativity, because I have always wanted to understand the subject, and I have just attempted to answer the following question (1-22) in the book: An electron ...
0
votes
3answers
64 views

Kinetic energy of an object

We know that motion is relative. So let an object(o) be moving with a certain velocity with respect to an object (A).If another object (B) is moving with respect to (A) at a given moment and they ...
0
votes
2answers
66 views

Is the weight of a bicycle frame significant compared to the body weight?

Some of my colleagues had a discussion about the question if the weight of a bicycle frame is significant compared to the weight of the rider‘s body. One argues that the weight of the frame can simply ...
1
vote
1answer
286 views

Galileo's law of odd numbers

The Galileo’s law of odd numbers states that the distances traveled are proportional to the squares of the elapsed times. In other words, in equal successive periods of time, the distances traveled by ...
0
votes
3answers
91 views

Sign conventions for relative velocity problems

I am having trouble solving relative velocity problems because I can't seem to understand the sign that goes along with the velocity of different objects. $$ v_{ac} =v_{ab} + v_{bc}. $$ How do the ...
-2
votes
4answers
73 views

What is the correct formula for relative velocity?

I have consulted byjus.com, HC Verma and Khan academy, all are saying different. byjus and HC Verma book is saying that formula for relative velocity is $V_a +V_b$ but in Khan academy they are telling ...
0
votes
2answers
80 views

Throw a ball AT a moving train, in what direction does it reflect?

You are standing at a platform, with a ball. a train approaches and u throw the ball at it in a straight line from a small distance. in what direction des the ball reflect off? heres what i think, ...
-1
votes
2answers
131 views

Does a helicopter that simply hovers remain in the same spot on earth? [duplicate]

Ignoring statistical variation in wind, will a helicopter that only applies force perpendicular to a perfectly sphere earth remain in the exact same spot relative to the earth? I am arguing with ...
0
votes
1answer
59 views

Speed of light as the maximum speed and movement course

Assuming we have 3 objects d,e,f moving on the same line while e is stationary, d is moving to the left at 'almost speed of light' and f is moving to the right at 'almost speed of light'. What is the ...
0
votes
0answers
14 views

Issue deriving observed period of a moving signal in different reference frames

Consider a receiver on Earth measuring radio waves from an incoming slow moving UFO. Here is my attempt to find the period of the signal as measured by the earth observer. T' is the period of the ...
-1
votes
1answer
37 views

Velocity of approach which changes continuously [closed]

There are two particles A and B which are moving with constant speed $v$ and $u$ such that $v$ is always directed towards B. At $t = 0$, the separation between A and B is $l$ and $u$ is perpendicular ...
0
votes
2answers
51 views

Throwing/Dropping an Object

When we throw or drop an object while moving, do we impart it our acceleration or velocity or both? Say i throw a ball at 5 m/s (relative to me) while at say, 30° to my direction of motion, then will ...
0
votes
1answer
67 views

Moving moon explanation

I saw the moon moving in a fast pace several times with the naked eye, even during day time when its cloudy. How is that possible? I asked my teacher about it and he said its just an illusion, but ...
0
votes
1answer
57 views

Time in Lorentz transformations

I have a question about the meaning of time in Lorentz transformations. When we say that event A for S' occurs at t', I understand that this ct' is a distance, but I wonder exactly what does it ...
0
votes
0answers
24 views

Vertically move in a helicopter to go somewhere on Earth [duplicate]

Is it possible to go from point A to point B (which are on same latitude) by hovering above A and wait till the earth rotates to point B below and then come down vertically? I believe there would be ...
1
vote
3answers
41 views

Defining what it means for a reference frame to move with a velocity $\mathbf{u}$ with respect to another

In describing a Galilean transformation, for example, one might say that if a reference frame $S'$ is moving at a velocity $\mathbf{u}$ with respect to $S$, then an object traveling at a velocity $\...
-1
votes
2answers
57 views

Relativity: moving space shuttles [closed]

Two space shuttles $A$ and $B$ are moving in opposite directions. A person on Earth measures $v_A = 0,75 c$ and $v_B = -0,85 c$. What is the velocity of $B$ relative to $A$ (= $v_{BA}$)? So my first ...
1
vote
1answer
106 views

Time when two particles will meet [closed]

Particle P moves with constant speed of 13m/s always aiming at O . As P starts moving , O moves with constant velocity of 5m/s towards positive y-axis. Time taken by particle P to catch O will be? I ...
1
vote
0answers
24 views

Time interval to closest approach between two sattelites [closed]

Two artificial satellites are in circular earth orbits in the same plane. The orbit radius of one of the satellite is $r$ and that of the other is slightly greater than the other i.e $r + \Delta r$. ...
1
vote
0answers
31 views

Relative velocity and pseudo forces

If I am in a spaceship moving in deep space....... which is accelerating.... There is nothing around to compare my motion with.... How can I say even if I'm moving or not....if I say I experience a ...
-1
votes
4answers
106 views

Why doesn't a ball thrown upwards fall behind us if we're moving forward?

If we consider ourselves traveling in a bus and if we a throw a ball upwards, the ball should fall behind us according to law of inertia, right? If so why doesn't the ball always fall behind us each ...
1
vote
1answer
44 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 ...
1
vote
1answer
38 views

Charged particle and magnet, can this event vary relatively?

suppose we take a charged particle and a magnet and place them at some particular distance apart .Now let's take 2 frame of reference. [the charged particle and the magnet are in rest with respect ...
0
votes
1answer
25 views

Deriving the equality between the external torque and the rate of change of angular momentum, for a system of particles

I've started working through Analytical Mechanics for Relativity and Quantum Mechanics by Oliver Johns and I'm stuck on deriving a formula. In the section titled "Change of Angular Momentum", Johns ...
0
votes
0answers
48 views

Why does a charged particle experience lorentz force while moving in a uniform magnetic field?

Firstly, when a charged particle moves in an infinite uniform linear magnetic field, it experiences a force.But,how does the charge or how do we differentiate that the relative position of charge is ...
-1
votes
2answers
44 views

Role of motion in experimental results

This page contains:"If you are in a closed room on a ship sailing at a constant speed and the ride is perfectly smooth...[t]here’s no physical experiment you could conduct to tell whether you’re ...
0
votes
0answers
97 views

Does absolute motion/stillness exist?

I am not a physicist :) I (think I) understand the idea that motion can be relative in the sense that, I'm standing still inside a moving train in regards to the moving train itself, but I'm moving ...