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

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2
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2answers
546 views

Exact definition of momentarily comoving reference frame (MCRF)

Consider a particle $P$ in the framework of special relativity with position $r(t)=(ct,x(t),y(t),z(t))$ respect to an inertial reference frame $\Sigma=(ct,x,y,z;O)$. I need to know if the following ...
0
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3answers
164 views

Animating an Acceleration Vector - Acceleration of object on a crested path in gravitational field

So I was reading in Chapter 3 of my textbook, Sears & Zemanksky's University Physics with Modern Physics by Young and Freedman, 13th Edition, and the discussion took us to a definition of the ...
0
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2answers
33 views

Horizontal and vertical acceleration of a ball on a slope?

I understand that you resolve the components of the balls weight parallel and perpendicular to the slope in order to calculate the force due to gravity that actually acts down the slope. The ...
0
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2answers
52 views

How to calculate the final velocity of object with variable acceleration? [closed]

Initially, an object has a velocity of 0 m/s and acceleration 8.44 m/s2. After traveling 500 km, its acceleration is 9.81 m/s2. How would you calculate the final velocity of the object?
-2
votes
0answers
15 views

Kinematics-Motion in one Dimension [closed]

A man is standing on top of a building 100m high. He throws 2 balls vertically, one at t=0 and the other after a time interval(less than 2s). The later ball is thrown at a velocity of half the first. ...
2
votes
3answers
82 views

Does acceleration follow the same addition like velocity?

Two frames have relative velocity $u$, but an object in one is initially at rest and in the other has velocity $v$. If it then starts to accelerate, the acceleration measured in both frames is equal. ...
3
votes
2answers
59 views

Shape and even connectedness of accelerating components in SR is frame dependent?

In some inertial frame consider a disk of radius 1 lightyear at rest. Then along the edge of the disk there are some people in spacesuits at rest hovering right above the disk (which has negligible ...
0
votes
1answer
83 views

Calculating jerk vs Fitts law for smoothness

I've tracked the movement of an input method resulting in this dataset. All data is tracked with equal intervals of 100ms. For example an iteration value of 4 means that this is the position of the ...
0
votes
1answer
18 views

How to draw a velocity curve from Engine power, weight and traction?

Not sure if this is the right forum but I would like to plot a velocity curve of a train, starting at 0km/h and accelerating up to a max speed. The data I have for the locomotive engines are: ...
5
votes
4answers
369 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 ...
0
votes
2answers
47 views

What objects' masses do we need to take into account when calculating force?

In the following problem: A steam engine of mass $3\times 10^4\ \mathrm{kg}$ pulls two wagons each of mass $2\times 10^4\ \mathrm{kg}$ with an acceleration of $0.2\ \mathrm{m/s^2}$. Neglecting ...
1
vote
1answer
122 views

What is the effect of Torque Steering on a motorcycle with a long wheel base

From experience, it appears motorcycles with a large wheelbase coupled with a long handlebar (say a modified Harley Ape Hangar) shows a noticeable tendency to veer to a side during acceleration vs a ...
0
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0answers
44 views

If a spaceship accelerates enough can it overcome spaghettification?

If a spaceship accelerates at the right amount would that counteract the spaghettification caused by falling into a black hole?
0
votes
1answer
70 views

Do black holes have a puff pastry point?

If a person falls into a certain sized black hole they accelerate very fast, which increases the g forces on them. These g forces flatten the person out into a pancake. As the person falls further ...
-2
votes
2answers
35 views

Save a falling person by nullifying their mass or reversing gravity [closed]

Let's say you have the superpowers to manipulate matter, mass and gravity. Imagine a person falls off a plane, flying few kilometers above the air, and they are about to get splattered onto the hard ...
0
votes
0answers
16 views

Could diamagnetism be used to create an airbag for your internals?

Could a massively strong magnetic field be used to shield a human body from the effects of excessive +/- accelerations? My understanding is that say for a pilot suitably strapped in that the strain ...
0
votes
2answers
83 views

Convert an equation for acceleration into one for velocity

A sledge is pushed in a straight line. Assume surface is smooth. When the sledge is x distance away from the start the magnitude of its acceleration is given by $0.08e^{-4x}$ and is going in the same ...
11
votes
3answers
625 views

Is acceleration an average?

Background I'm new to physics and math. I stopped studying both of them in high-school, and I wish I hadn't. I'm pursuing study in both topics for personal interest. Today, I'm learning about ...
0
votes
2answers
121 views

Changing directions with a constant speed?

I'm currently working on a problem in which an object's speed remains the same, but it experiences a change in direction after some time. I'm fairly sure it experiences an acceleration in order to ...
3
votes
2answers
173 views

General Relativity and acceleration

Suppose I am riding an amusement park ride. This ride is a circular Plexiglass structure that spins at high speed. If I measure the circumference of the structure(while the ride was spinning) with a ...
3
votes
1answer
117 views

Energy for acceleration towards speed of light is relative?

This seems a very simple question - and I guess it will turn out to be so. It's a given that accelerating particles with mass towards the speed of light takes more and more energy (ultimately an an ...
0
votes
0answers
36 views

MEMS Accelometer and Gyroscope data fusion for counting cycles

I will simplify my scenario as follows: a 6-DOF MEMS gyroscope and accelerometer unit is placed on the edge of a rotating wheel and the goal is to count the number of cycles using any of the units of ...
1
vote
2answers
56 views

Which moment of intertia do I need to calculate torque

I'm trying to calculate the torque needed to rotate an array of solar panels. I've found some formulas for calculating torque, but they require moment of inertia. I designed this array in Autodesk ...
0
votes
1answer
27 views

The equivalence principle and experiments concerning it?

Imagine that we are in a rocket accelerating with some magnitude $a_1 = dx^2/d^2t$, also imagine that we have a stationary rocket ship in close proximity to ours, stationary relative to our reference ...
0
votes
2answers
123 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 ...
-3
votes
6answers
110 views

A contradiction statement to $F=ma$ [closed]

If I thrown an object of mass 1 kg up in the air it will always fall with an acceleration of 9.8m/s. If I throw it very high up in the sky, it falls with a greater force as compared to if i throw it ...
3
votes
1answer
26 views

How does a body accelerate that is put into a flow field with constant speed?

Imagine an infinitely long flow channel filled with water flowing at a constant speed everywhere parallel to the infinitely long dimension of this channel. Furthermore, imagine we place a body (say a ...
0
votes
2answers
48 views

Barrel length, not PSI, determines acceleration?

In 5:49 in this MythBusters video https://www.youtube.com/watch?v=74K3IYOM7Lg, the MythBusters Jamie and Adam believe that barrel length is the deciding factor in acceleration, more so than PSI. Why ...
3
votes
2answers
192 views

How to use an accelerometer to correctly quantify the magnitude of vibrations

Consider the following setup: An accelerometer is placed inside a helicopter, measuring $g$ values along three axes $(x,y,z)$ every $10~\text{ms}$ (100 times a second), during a helicopter flight. ...
0
votes
2answers
69 views

Does acceleration warp space?

I know that mass warps spacetime and gravity and acceleration are equivalent so does acceleration warp spacetime too?
0
votes
3answers
687 views

How does artificial gravity reduction (weightlessness) work on Earth?

Some of us have been to those amusement park/carnival/theme park rides where you enter some capsule/machine, and you will float, etc. There is also some other thing where you go inside a big room ...
0
votes
1answer
84 views

Why we can't define energy in accelerating frame?

In my old unanswered question about accelerating frame, I have found (later after editing that question), that one of the keys is that energy is not defined in accelerating frame. What I do not ...
0
votes
1answer
52 views

Current Electricity

If $$ \frac{dQ}{dt} = I $$ and if an accelerated current produces E.M. waves (radiation), does that mean $d^2Q/dt^2$ (second derivative of a charge w.r.t. time) will give me the magnitude of the wave ...
0
votes
1answer
40 views

Boat Deceleration on Collision [closed]

I have a question regarding acceleration. When a boat collides with tires and they compress on contact and the boat is slowly brought to a stop, how is deceleration factored into this? As in, what ...
-1
votes
2answers
50 views

Does light ever experiences acceleration? [duplicate]

Till now I have learned that light has fastest speed. But I have also noticed that wherever it travels it only experiences retardation. So I wanted to know if light ever felt acceleration naturally in ...
2
votes
3answers
59 views

Einstein's principle of equivalence; Standing on earth vs sitting in accelerated car

When I am seated in a car that is accelerating in a particular direction I could, for example, throw a ball and it would appear to be flying the opposite way. With the windows covered etc. An ...
0
votes
1answer
25 views

Velocity change of air down a cone?

Does the velocity of fluids(specifically gasses) change when traveling down a cone from the wide opening to the narrow opening? If so, is there an equation used to calculate the acceleration or ...
2
votes
2answers
51 views

Will the gravitational pull of air affect the falling rate of an object?

After looking at this question: Don't heavier objects actually fall faster because they exert their own gravity? A thought occurred to me that due to the increased gravitational pull of the ...
-1
votes
3answers
55 views

Velocity and acceleration with variable friction

If you have a body on a table,with a velocity $u_0$, going from a non friction area to a friction area, how do I find the function for velocity and acceleration due to the variable friction force(T). ...
28
votes
8answers
7k views

Why does a free-falling body experience no force despite accelerating?

Note: For the purposes of my question, when I refer to free fall assume it takes place in a vacuum. From my (admittedly weak) understanding of the equivalence principle, falling in a gravitational ...
1
vote
2answers
2k views

Calculate speed from accelerometer

I am trying to use my accelerometer on my mobile device (smart watch to be specific) to calculate a persons arm swing speed. The data returned from the accelerometer is in $m/s^2$. Since the ...
0
votes
1answer
31 views

Calculate constant acceleration for a length of track with start at rest and final velocity known [closed]

My maths and physics are rusty... I'm a bit ashamed, but I have this problem: Let's have a 1000m linear accelerator (mass driver) propel a payload at constant acceleration, with a final velocity of ...
2
votes
7answers
560 views

Free fall into circular motion

If I'm on a roller coaster free falling from height $h$ and then suddenly start going into horizontal motion with a radius $r$ of turn what is the $g$-force I experience? I worked out the equation ...
0
votes
1answer
17 views

How to calculate the “angular braking distance” when you know the following values?

I have to calculate the arc length in radians that a circle spinning at speed will travel when it decelerates to $0$. I have the initial angular velocity in rad/s, the radius in meters, the mass in ...
4
votes
5answers
451 views

Intuitive answer to a kinematic problem

The problem: Two particles A and B start from rest and move for equal time on a straight line. The particle A has an acceleration a for the first half of the total time and 2a for the second half. ...
0
votes
2answers
29 views

Engine fuel consumption vs power

Something that has bother me for a long time is why a 600 hp engine uses more fuel per kilometer than a 80 hp engine. Let pretend I have two equal cars (same shape same weight etc) except for the ...
3
votes
7answers
826 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 ...
0
votes
2answers
59 views

Calculating acceleration of a car going downhill [closed]

Let's say a car is driving down a hill. Throughout the descent, you have access to the car's speedometer, a stop watch, and GPS altitude readings. You also know the car's mass if that helps. How would ...
3
votes
1answer
58 views

What force decays an oscillating charge?

Consider this scenario: We have a charge on a spring. As it oscillates, it loses energy to radiation. What force decays the oscillation? As far as I can see, the only forces in the scenario are ...
1
vote
1answer
45 views

Condition for 2 bodies to move together

The condition for 2 (or more) bodies to move such that they are always in contact, is that their accelerations (and velocities) along their common normal should be same. Can someone explain why this ...