# Questions tagged [acceleration]

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

2,010 questions
Filter by
Sorted by
Tagged with
194 views

### Why is Speed of an object equal to square root of distance traveled multiplied square root of acceleration?

I wanted to find the relationship of the speed of a falling object in a vacuum at g=9.8 m/s2 compared to its distance. I wanted to get time out of the equation. When I plotted the relationship it ...
24 views

### How to calculate acceleration using ADXL345? [duplicate]

I am trying to measure the acceleration and deceleration of a bike by using an 3 axis accelerometer (ADXL345). I know the formula of calculating acceleration using the $x,y,z$-components with respect ...
57 views

### Forces acting while running

If I am running on a surface with friction with no air resistance and also accelerate then net force acting on me is F=ma. The friction acts opposite to direction of motion and is less than the forces ...
30 views

### Calculating the distance crossed by a ball under changing gravitational acceleration [duplicate]

Suppose a ball of finite mass is taken to such a height in space that the gravitational acceleration decreases significantly. Now, as you let go of the ball, it should head straight down towards the ...
86 views

### Confusion about derivatives along worldline in general relativity

I just began learning general relativity and I am quite confused with what I'm learning. I understand that in special relativity, the four-velocity is $$U^\mu=\frac{\text{d}X^\mu}{\text{d}\tau}$$ and ...
64 views

Consider two events $\mathcal{A}$ and $\mathcal{B}$ corresponding to the beggining and the ending of trajectories of two massive particles, respectively. The particle named $\mathcal{P1}$ is in free ...
45 views

### Confusion about gravitational field strength and gravity?

Do all objects on earth experience the same gravitational field strength and if so why does weight, which is defined as the amount of gravity acting on an object, change? I think I am confusing ...
91 views

### Which interval encompasses the greatest deceleration, '$a$ to $b$' or '$c$ to $d$'?

Here we have a vehicle, that accelerates, decelerates suddenly, gains a little more speed and then decelerates until it stops. [The x axis is for the time in seconds!, t(s) the photo didn't ...
98 views

### What is happening with the horizontal component of the Earth's centrifugal acceleration?

We know that the equator has the highest centrifugal acceleration caused by the rotation of the earth (a = 0.034m / s2) but it is negligible because the vector of the acceleration of gravity is much ...
45 views

### Acceleration of a Point on the Edge on a Rolling Cylinder

Consider a cylinder with radius $R$ rolling without slipping to the right. The center of mass is rolling with a velocity of $v$. Consider the left most point, $p$, on the cylinder. What is the ...
57 views

### Division of force and acceleration!

As you would know that $\text {Force}= \text {mass} \times \text {acceleration}$. So $\text {mass}= \text {force}\div{\text {acceleration}}$. Now both force and acceleration are vectors. But their is ...
56 views

### How to convert acceleration projection to angle?

See a simple webpage here, for an object, if one know the acceleration in three direction $\hat x, \hat y,\hat z$, one could extracted two of the angle of the object between the plane that's normal ...
42 views

### Will the acceleration of a triangular wedge affect relative acceleration of a particle parallel to the inclined plane (the wedges surface)?

I was wondering if the horizontal acceleration of a triangular wedge will effect the acceleration of a particle on the wedges surface (because the wedge is triangular this will be an inclined plane) ...
848 views

### What's wrong in stating that equal gravitational forces act on two identical masses at different heights, as they have the same acceleration $g$?

This might be stupid but I need an answer. Newton's second law stated that the force exerted on a body equals the mass of the body times the acceleration of the body. And the law of gravitation ...
42 views

### Is there an upper bound on the amount of friction a body can generate?

Through some driver's ed class i encountered a claim stating that a car traveling at 30 kmph has a minimal braking distance of 8 meters (The specific number is not important). My question is whether ...
46 views

### When to use what centripetal acceleration? [closed]

There are two equations for it: $a_c = v^2 / r$ and $a_c = \omega^2 / r$. It seems like they give me different values. I don't know when to use which. Can you explain?
94 views

### Isn't the standard proof of a classical electron's orbit invalid?

There is an excellent answer to the question of classical electrons falling into nuclei here. But the very first step is to state that $ma=m\frac{v^2}{r}$, Newton's law for a centripetal force/...
41 views

### What is the physical interpretation of this limiting case of a block on a wedge?

I have a question about the physical interpretation of a particular limiting case in a problem. Please note my question is not about how to actually solve the problem, but rather an entirely ...
144 views

### If gravity is simply a curvature of space, why does it accelerate objects? [duplicate]

I understand how an object moving through space would be affected if gravity were a curvature of space as opposed to being a force. However, I do not understand why this creates a "pull" on an object. ...
91 views

### Lorentz non-invariance of $3$-acceleration

$3$-acceleration can not be constant in a relativistic system. Because $\vec a^2$ is not Lorentz invariant. Does it mean that Lorentz invariance works only for $4$-vectors? How this should be ...
32 views

### Acceleration vs velocity on a scale

I am unsure about this thought experiment: I stand on a scale with some weight in my hands. When I move the weight upwards, the scale shows a higher number for some time. This is clear to me as I ...
189 views

### Horizontal acceleration on an inclined plane [closed]

Assume the inclined plane to be fixed. Taking components of gravitational acceleration along and perpendicular to the inclined plane and further taking a component of the component along the plane in ...
85 views

### Conceptual freshman year physics question about acceleration

A particle moves along the x-axis. When its acceleration is positive, A. its velocity must be positive B. it must be speeding up C. it must be slowing down D. its velocity must be negative E. none of ...
147 views

### What does the area under an acceleration-displacement curve represent?

Considering the equation where, $$\frac {1}{2} \left (v^2_f - v^2_i \right) = \int_0^s ads\,$$ What does the left-hand side of the equation actually represent? Is there an intuitive explanation ...
132 views

### Acceleration-Meter [closed]

I encountered a Physics Olympiad problem: A ball bearing rests on a ramp fixed to the top of a car which is accelerating horizontally. The position of the ball bearing relative to the ramp is used as ...
76 views

### Can everything be accelerating away with a nearly constant Hubble Parameter?

Simple Physics shows everything accelerating away over time with a nearly constant Hubble parameter. The velocity of recession is $V=DH_o$: The change in distance over time is $∆D=V∆T=DH_o∆T$: The ...
117 views

### Graph analysis of accelerometer data

I used my mobile accelerometer sensor to collect data from a moving bike where I held it in my hand in a way that the smartphone sensor +Y axis is in the direction of the moving bike always. This can ...
137 views

### If I am decelarating forwards am I accelerating backwards?

If I am in a car and I put the brakes on so that I am slowing down (decelerating) am I then accelerating backwards? e.g. If I am decelerating in this car at -5ms⁻² am I accelerating backwards at 5ms⁻² ...
44 views

### Proving braking distance formula $x = \frac{v_0^2}{2 \, \mu \, g}$ [closed]

I'm tried to prove the braking distance formula: $$x = \frac{v_0^2}{2 \, \mu \, g}$$ with $v_0$ initial speed, $\mu$ static friction coefficient, $g$ gravitational acceleration on the earth. ...
62 views

### How do I calculate final velocity from acceleration, displacement and inital velocity?

How do I calculate the final velocity ($v_f$) given a known constant acceleration ($a$), a known inital and final position ($x_i$ and $x_f$), and a known inital velocity ($v_i$), where $v_i$ can be ...
97 views

### Is the car braking time formula $T = v / (\mu_s \, g)$ valid only for uniformly accelerated motion?

I'm wondering if the car braking time formula is valid only for uniformly accelerated motion. $$T = \frac{v} {\mu_s \, g}$$ with $v$ average speed, $\mu_s$ static friction coefficient between ...
29 views

### Can accelerating spaceship somersault in space?

I was watching a space shuttle performing a pitch manuver in free fall, then I imagine a spaceship travelling with a constant acceleration in space trying to perform pitch manuver is it possible while ...
145 views

### Arbitrary frames in special relativity

Consider this quote by James J. Callahan in his book The Geometry of Spacetime where he summarizes the conclusions of his chapter on arbitrary frames in SR (page 165): Once again we find that the ...
90 views

### How to derive acceleration addition formula in special relativity

After seeing the derivation of the velocity addition formula (wikipedia) I want to use the same approach for deriving the acceleration addition formula. My understanding of velocity addition ...
105 views

### Difference between different radial and centripetal accelerations:(Doubt)

In cylindrical coordinates I had derived the acceleration as : for the first component of acceleration, what is the difference between radial and centripetal ?
593 views

### What is more harmful in a car crash - restrciting movement or allowing some movement to reduce g-force?

Sorry if I haven't worded the title very well, feel free to improve. Let me explain before I ask my question... We have purchased a car carrier (small version) for our dog and also purchased some ...
209 views

### If $F=ma$, why do we need speed limits?

This may be a really stupid question, but I am learning mechanics and asked myself with this question: What exerts more force when it hits an object: a car driving at a constant speed of 40mph, or ...
66 views

### Equations of motion for an object with non-constant acceleration related to its velocity [duplicate]

If I have an object flying through space with an initial velocity $v_0$ and undergoing constant acceleration $a$, then I can easily compute its velocity or displacement at any point in time $t$ using ...
478 views

### An inertial frame of reference observes an object on which the total force is zero but still has non-zero acceleration

Imagine a cup stuck to the floor of a falling elevator with the help of some impressive adhesive. In a frame of reference is this cup is being watched through the walls of a transparent elevator, this ...
50 views

### Sign of gravitational acceleration

The gravitational potential energy comes from the formula $mgh$ where $g$ is always $>0$. But when we get to choose it's sign? I figured out, it really depends on what you choose as positive axis ...
72 views

### Can the acceleration of the object thrown by man exceed the acceleration of gravity? [closed]

Can the acceleration of an object thrown by man exceed the acceleration of gravity? I don't think so. Otherwise, how could the object fall back to the ground?
82 views

### Why is the tension force equal to the applied force when someone is lifting themself with a pulley? [duplicate]

While I can get the right answer for these problems by memorizing how to do it, I want to understand it conceptually. There is a (massless) pulley with a rope through it. A person sits (in a bucket/...
82 views

### Why is this $v > c$ example wrong? [duplicate]

Take an acceleration equal to g for 1 year. Isn't the speed of light reached? And exceeded after this time? In the Indian journal Pramana Soviet's scientists made this argument. They explained we ...
12 views

### Does the emission of Larmour Radiation by an electron require additional force to be applied to achieve a given velocity?

Accelerating a charge causes the emission of radiation, but I can't find a clear answer as to whether or not an electron loses kinetic energy as a result of this: https://en.wikipedia.org/wiki/...
90 views

### Gyroscope - Transform data to correct coordinate system

I have some data on linear acceleration ($m/s^2$) and angular velocity ($rad/s$) recorded from an electronic sensor over time. I realized that the sensor had been displaced in its position during ...
241 views

### From a traveler's point of view, what prevents him from reaching the speed faster than light?

I have read the answer to this question from Eric. That answer is still from the point of view of a standing observer that sees the traveler spending infinite amount of energy. My question is asking ...
118 views

### From a traveler's point of view, what prevents him from reaching speed faster than light? [duplicate]

From a traveler's point of view, as he is accelerating with $1g$, in under one year he would reach the speed of light. Note that from his point of view, everything looks normal so he could keep ...
27 views

### Rolling friction. Hard wheel and soft floor vs soft wheel and hard floor [closed]

Are rolling friction coefficients the same in the cases above? I was only able to find the literature for the soft wheel / hard surface case. My problem is the following. I am trying a accelerate a ...