All Questions
Tagged with relative-motion reference-frames
170
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What will be the total work done by friction on the system (man+boat)? [closed]
As I am seeing this, the man and boat will have different displacement from ground frame, so there should be a net work done by friction . The books says, total work done by friction is zero when ...
- 35
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4
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239
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Motion and the Universe
In physics class today, I learned that motion is relative, and to determine if an object is moving or not, you need to have a stationary reference point.
Well, that got me thinking:
How can you ...
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3
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419
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If Earth accelerates, what reference frame is its acceleration relative to?
It should be a very fundamental thing, a very simple question. But there's something I want to understand.
We know that when we throw an apple vertically upwards, it experiences a force of gravity ...
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I'm in a moving train filled with vacuum. I'm leaning to the rear wall, so the train pushes me forward. If I drop a ball, woudn't it hit my chest?
I'm assuming it has inertia, so no, it would continue to move forward and just fall to the the ground of the train. But has anyone really performed this experiment in a vacuum? In the absence of ...
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From the frame of reference of a colliding object, does the entire universe change direction when it bounces?
Consider three objects: a rubber ball, a spaceship, and an isolated brick wall floating serenely in the vacuum of space.
From the perspective of an observer on the spaceship, the ball is moving ...
- 103
44
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Is there any physical evidence for motion?
Let's say that we have 2 tennis balls in space, one being in motion (say, pushed by an astronaut), and the other one still.
If we could take a snapshot of both tennis balls, would there be any ...
- 591
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298
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How to conceptualize Newton's apple?
I have no physics background, which is the genesis of my question.
In pop-science, it is frequently mentioned that Newton's apple didn't fall toward his head, but rather that his head came up and ...
- 141
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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 ...
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73
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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. ...
- 558
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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....
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523
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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 ...
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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 ...
- 13
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2
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71
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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 ...
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26
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12
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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 ...
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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,...
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