The rate of change of velocity of a body per unit of time.

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129 views

Explanation for “if all accelerated systems are equivalent, then Euclidean geometry cannot hold in all of them”

I'm doing an EPQ (mini college research paper) on gravity, and I found a site that explained things in simple terms. I am having trouble understanding how Einstein came to his revelation space-time ...
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4answers
279 views

How is acceleration measured if there is change only in the direction of velocity & not magnitude?

The formal definition of acceleration is It is the measure of how fast the velocity changes with respect to time. Now, when the magnitude of velocity changes, acceleration $$\vec{a} = \frac{d ...
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1answer
74 views

What matters more in the strength tester game at a carnival, momentum or force?

A buddy and I were arguing over which matters more in the strength tester game (assuming the same accuracy of the hit): 1) momentum or 2) force. He was arguing that if you swing the hammer directly ...
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1answer
113 views

Rate of acceleration for two hanging masses in two experiments

I conducted an experiment where two masses of different weight were attached by a string and fed through a pulley. The difference between the masses was $0.025\: \mathrm{kg}$. The lighter mass was ...
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1answer
172 views

Finding acceleration and distance when velocity given

I am trying to do the following question for practice (it is an interview question), and I don't know if my methods and answer are correct. Given a velocity $v=2+3t^2$, find acceleration after 3 ...
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0answers
128 views

Is the gravitational acceleration at the event horizon constant?

If the escape velocity at the event horizon of a black hole is equal to the speed of light, does this imply that the gravitational acceleration at the event horizon is also constant? For example, ...
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1answer
209 views

Burning fuel in space while accelerating and deaccelerating

Is it true that for acceleration in space we need not the same quantity of the fuel than during the deacceleration stage?
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1answer
225 views

Finding Acceleration of Two Masses in an Ideal Pulley [closed]

I am stuck on this problem: Two masses are connected by a string which goes over an ideal pulley. Block A has a mass of 5kg and can slide along a rough plane inclined 30 degrees to the horizontal. ...
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3answers
151 views

How to describe arbitrary accelerations in special relativity

Describing acceleration in special relativity is in principle straightforward, and for simple cases the resulting transformations are simple. Examples include circular motion and constant acceleration ...
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4answers
333 views

Why does objects with zero acceleraton move?

My question is, if we apply a force on an object to move it with a constant velocity, of course it will move. But what I don't understand is, why will it move? From Newton's law F=ma and in this case ...
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2answers
263 views

How long does force apply?

If you were to throw a ball into the air while standing on earth, it will take some time to grow from zero relative velocity to it's maximum height before the velocity starts to increase again as its ...
2
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1answer
211 views

Mass, Acceleration, and Force

The Problem: (a) A car of mass m is on an icy driveway inclined at an angle of 20$^{\circ}$, Determine the acceleration of the car, assuming that the incline is frictionless. The questions is ...
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7answers
790 views

Help understanding Bell's spaceship paradox

The problem statement of Bell's Spaceship paradox is this: Two spaceships float in space and are at rest relative to each other. They are connected by a string. The string is strong, but it ...
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2answers
124 views

Relativity and acceleration-acceleration

Presummary to save expert's time! (pls see below!) "In GR, is jerk relative?" As I understand it, "Special Relativity" (special meaning, specific limited situations) applies only for (in a word) ...
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5answers
481 views

High speed does not kill. Does acceleration do it ? or jerk?

In a recent question the OP asked why high speed will not kill us. The accepted answer, highly upvoted, stated very first that Speed doesn't kill us, but acceleration does. The second answer ...
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3answers
80 views

Power and velocity?

If $P=Fv$, power is constant and the power is the rate of change of kinetic energy, i.e. $$P = d(mv^2/2)/dt,$$ what must $v(t)$ be to satisfy this equation?
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0answers
63 views

In the formula for the change of frame of reference, which term(s) is/are the centrifugal/centripetal acceleration?

This is the formula for the change of frame of reference for the acceleration: I have a book where it is written that: The first term is the absolute acceleration. The second term is the relative ...
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0answers
49 views

Trying to model the acceleration of a system due to an impulse forcing function

My team and I are working on a design project to design/modify a device that can go on hikes for paraplegic/quadriplegic people. Here is the current design (not designed by us): We are thinking ...
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4answers
156 views

A question on force and acceleration

Q 1. Two bodies, $m_1$ and $m_2$, in contact with each other, are under constant acceleration $a$ in the same direction. Find the force exerted by $m_1$ on $m_2$. A similar question with my ...
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2answers
82 views

Determining Acceleration Based On Graph

I understand how to solve this problem, but I am unsure how to generate an equation for the graph (below). My current attempt involves using the mass provided along with the derivative of the line ...
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2answers
151 views

Perceived acceleration in an artificially modulated gravitational field

It's intuitive that while accelerating in a locally constant gravitational field, there is no perception of acceleration, since the body accelerates uniformly. What if a body were in a rapidly ...
15
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5answers
6k views

How fast would someone have to run to travel vertically up a wall?

I am currently doing a physics project on the effects of so-called 'super-speed'. I was wondering how fast you would have to run to vertically travel up a wall? That is, to negate the force of ...
1
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1answer
86 views

Confused about gravitational potential energy [duplicate]

So learning the concept of gravitational potential energy, my professor says that when lifting an object without any acceleration, the force we exert on the object to lift it is the same as the force ...
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1answer
194 views

How to model a very simple spinning wheel

First off, I'm not a physics person, just a lowly software engineer with below average math skills. What I've written is a simple animation of a spinning wheel using C++/GTK/Cairo. It allows the user ...
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2answers
350 views

For a massless pulley moving upwards with acceleration, is the upward force equal to the downward force?

Imagine a massless and frictionless pulley with two weights hanging either side of the pulley by a massless string. Like this except not attached to a ceiling Rather than being fixed to a ceiling, ...
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0answers
28 views

Limit to accelerate an object? [duplicate]

Caianiello's maximal acceleration says $\mathcal{A}_m = 2mc^3/\hbar $. But this seams to be a bit counter intuitive to me. A higher mass can be accelerate faster? First question: Why? The paper talks ...
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1answer
126 views

The 3rd derivative of the size of the universe?

We know the size of observable universe, that it is expanding, that expansion is accelerating. Does sufficiently precise data exist to determine at least the SIGN of the next (the 3rd) derivative? ...
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2answers
106 views

Orientation of a rocket going in a circle?

This problem is from my physics homework: A rocket is moving at constant speed in a perfect circle in deep space, far away from any planets or stars. The diagram below shows the circle the ship ...
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2answers
130 views

Converting velocity-time line to acceleration-time?

How would one find where the straight line on a VT graph is on an AT graph? For example in the above image, if I were to convert that into an acceleration-time graph, where on the y-axis would the ...
2
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0answers
149 views

Odd experiment results (electromagnetics)

Okay, a bit of background. So I'm working on a linear accelerator (you might know it as a Gauss rifle), and I had worked through the equations I thought I needed (Magnetic force, displacement, etc.) ...
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3answers
274 views

How does an electron undergoing uniform circular motion exactly lose energy?

One of the main reasons for the failure of the Rutherford model of atomic structure, it is famously stated, is that the electron undergoing circular orbit loses energy since due to its centripetal ...
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2answers
64 views

Constant vs increasing acceleration for reference frames

I was reading this webpage created by a professional physicist and was shocked regarding his statement on constant acceleration not being sufficient for producing the old "ball flies into the ...
4
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1answer
170 views

Does accelerating generate gravitons?

If gravity and acceleration are indistinguishable, then does that mean converting potential energy to kinetic energy generates gravitons... but only temporarily until you stop accelerating?
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1answer
95 views

Distance as a function of time where acceleration changes with respect to distance

I was thinking the other day about gravity. I know that acceleration in a magnetic field changes with respect to distance from the center of the field. So I was thinking, how would one find the total ...
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1answer
111 views

Do Photons Accelerate Upon Creation? [duplicate]

Of course the speed of light is constant relative to everything. Its frequency can change, but its speed is constant. Photons may be absorbed by atoms or release by atoms as energy, but as soon as it ...
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2answers
84 views

Does Centripetal Force Change Direction?

I have been struggling with this question that I have, "Does centripetal force change direction?" From every point, it points to the center. But if we draw its vector, we draw the tails from ...
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1answer
97 views

Gravity of the accelerated particle in General relativity?

Suppose heavy particle or body ("billiard ball") is accelerated with very thin and very rigid (not absolutely rigid) rod of infinitesimal (not zero) mass ("cue stick") Acceleration is constant in ...
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1answer
84 views

Accelerating beyond the speed of light? [duplicate]

Suppose you have a lot of fuel in your spaceship, in deep space - enough to accelerate at 1mss for a long time. What would happen once you are travelling close to the speed of light? Could you reach ...
3
votes
1answer
104 views

Units of acceleration & Newton's 2nd Law

I tried to use Newton's second law, $F=ma$, to calculate the acceleration of an object. \begin{align}\frac{F}{m}&=\frac{ma}{m} \\ a&=\frac{F}{m}=\frac{30\,\rm N}{1.2\,\rm ...
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1answer
441 views

Finding the acceleration given only an angle

This is one of my homework problems for a College Physics I course: Dana has a sports medal suspended by a long ribbon from her rearview mirror. As she accelerates onto the highway, she notices ...
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2answers
360 views

Derivation of the average Velocity formula with constant acceleration (using calculus)

I have been looking at $$ v_{avg} = \frac{v_{i} + v_{f}}{2}, $$ when the acceleration is constant, where $v_i$ is equal to the initial velocity and $v_f$ is equal to the final velocity. How can ...
3
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4answers
519 views

Is a causal relationship implied by Newton's 2nd Law?

Throughout my time learning physics I have been imbued with the notion that forces cause accelerations, period. Accelerations don't cause forces, and they aren't merely correlated phenomena. By ...
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1answer
116 views

How much fuel is needed for a constant-acceleration rocket?

My son and I have been discussing the concept of a constant-acceleration rocket, as described here and here. We're willing to assume advanced technology such as a fusion rocket, which, according to ...
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0answers
15 views

Help with Kinematics and trajectory [duplicate]

I am asking this again because it was closed and I didn't receive a response. So a baseball is hit with a velocity of 30 m/s at 42.6 degrees to the ground. A fielder who is supposed to catch the ...
3
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2answers
2k views

“Magic” Speed to Drive Over a Speed Bump: Myth or Reality?

A somewhat controversial aspect of speed bumps (sleeping policemen for those in the UK) is that they arguably cause more loss of life than they prevent by acting as a hindrance to emergency response ...
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1answer
150 views

A question about finding average velocity and average acceleration

I have trouble understanding the following problem's answer: Which of the following relations are true for any arbitrary motion in space? (a) $v_{avg}=\frac{r(t_2)-r(t_1)}{t_2-t_1}$ ...
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1answer
167 views

Direction of radial acceleration same in circular motion?

I have a big confusion. There is a question in my book which basically says that a ball is tied to a string and rotated. and it asks me to tell whether the following statement is true of false. ...
1
vote
1answer
700 views

How to use accelaration data of moving object to calculate distance?

I read couple of similar question on this forum and few blogs on web, though I am still confused,I am determined to calculate object displacement using accelerometer data. So, I tried using ...
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votes
2answers
522 views

If gravitation causes constant acceleration why moon does not fall into earth? [duplicate]

If moon travels with constant speed in one direction and earth gravitation causes constant acceleration in perpendicular direction why moon does not eventually fall into earth? I mean if gravitation ...
1
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1answer
184 views

Angular acceleration and linear acceleration

I have a small confusion. I learned very recently that all particles of a rotating body have the same angular acceleration but different linear acceleration (same for velocity as well). But how is ...