Acceleration Definition and 1000 Threads

It seems to me as the space between galaxies expands it reduces the gravitational attraction between them. Assuming that this is happening between the majority of the galaxies in our Universe it would cause the acceleration of expansion by a factor of 1/r2.

Hi, I need to come up with a math model for a digital ignition system. I've been thinking about it and I think that I need to measure 2 things to be able to calculate when I have to start charging the coil. They are the angular velocity and the acceleration but how can I do it? the idea is to...

I would really appreciate some help with this problem regarding non-uniform circular motion, in which a body is accelerating as it follows a circular path. If we take Example 1, a body starts at Point A with an angular speed of 180°/s. The body accelerates to Point B and reaches it some time...

Summary:: I wish this video (and YouTube in general) was around when I took intermediate level mechanics as an undergraduate physics student: I wish this video (and YouTube in general) was around when I took intermediate level mechanics as an undergraduate physics student:

I had deduced that B,E,H are the places where acceleration will be zero, but when I read the solutions it showed that K also has a = 0. It said it had maximum slope and then said a = 0. But I couldn't understand why? Please help.

The force is driving the rotation is gravity. My question is that what is the track acceleration? How do I calculate it?

it sounds like you just need to use F/m = a which gives 25 / .76 = 32.89 = a this didn't work so I tried to get the x component of acceleration so I did 32.89cos(45) = 23.26 and this didn't work. what am I missing, the force is tension right so it should be 25N?

All spacecraft that have been put into orbit around other planets have required engines to decelerate them and inject them into their orbits. So-called "ballistic capture", from what I've read, always seems to call for at least a minimum application of force to change the trajectory; I get...

I want to derive an acceleration in the case for a stationary mass in the gravity field. I found the total energy in the GR is provided by a simple equation: https://en.wikipedia.org/wiki/Schwarzschild_geodesics ## E = mc^2\sqrt{1 - rs/r} * \gamma ## So, this is easy to provide acceleration...

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For this question the ball is rolling without slipping so that means the velocity of the point of contact is zero. Does that also apply to the acceleration of the point of contact? Because that’s what I assumed and I applied the relative acceleration formula above and use the starting point to...

Consider the inertial reference frame in which the positive ions forming the crystal lattice of some portion of a metallic ring are at rest. In this frame, an inertial force of mra exists. Consider the electrons in this portion of the metallic ring. The inertial force of mra is exerted on the...

So I tried the problem and it’s different from the solution. I’m confused on why my attempt didn’t work, is it because the wheel is undergoing general planar motion? I tried to just apply Newton’s 2nd law to find the acceleration of the centre and then use that to find angular acceleration. The...

Hello, Some doubt arose me reading this thread https://www.physicsforums.com/threads/is-acceleration-absolute-or-relative-revisited.999420/post-6454462 currently closed. Sorry, I have not be able to quote directly from it :frown: Your claim is not , however, asserting that the spacetime...

The function x (t) = 4 (m · s) t − 1 + 10 m describes the position of a mass point. In which direction does the speed point at time t = 1 s? Is the amount of speed constant or not? does the velocity function change its sign for t> 0 at some point? And in which direction does the acceleration...

I understand that any accelerating charged particle will emit a photon. But I do not understand how the rate of acceleration relates to the photon that is emitted. For example: If a proton is falling to Earth in a vacuum at 9.8 m/s^2, then what are the characteristics of the photon that will be...

[Mentor Note: Two threads with similar titles merged] First calculate the equivalent force on the car from the max torque. An average tire is 15 inch diameter = about .2 meter radius Since T = F X R , F = T/R = 660/.2 = 3300 Newtons. since F = M X A, A = F/M = 3300/2083 = 1.6 m/sec^2...

In a inertial frame of reference ##S## body accelerate with constant acceleration ##a##. Can then exist inertial frame of reference ##S'## which moves with speed ##u## relative to ##S## in which body does not accelerate? And why?

Let me imagine a box placed on a table. It has got no acceleration. If I were a person who trusted Newton's laws then I would argue that the net force on the box should be zero. Now in another situation I am an observer outside the Earth and I see that the box is rotating along with the earth...

I thought I'd start by writing the problem in a tensor formalism. I have identified with ##S## the Earth and ##S'## the rocket. Since the acceleration provided is in the rocket's frame of reference, I can write the following four-vector. $$ a'^\mu=(0, a, 0, 0) $$ Since we are interested in the...

Hi everyone, I'm working on designing a vehicle that uses electric motors, but I'm having a little trouble finding the load and acceleration torques in order to select the right motors to use. Variables: m = total mass of vehicle a = acceleration μ_r = rolling friction coefficient r = wheel...

I am doing an Atwood Simulation lab. I am having trouble with this part of my lab that ask the question provided. I can tell that the relationship is linear and that as the mass increases at a constant rate the acceleration increases. Logger pro tells me that the slope is 31.43. I am having...

I have been wondering, and curious as well, and thus I would like to ask: Generally, are acceleration as in reaching top speed or zero speed from top speed and acceleration in terms of changing direction equally easy for human beings at average and normally, or is changing speed easier than...

80km/h = 22.2 m/s Through momentum: 1940(v_f) = 540 (22.2) + (1400)(-22.2) => v_f = -9.84 m/s I figured the work that the energy lost in a collision is equal to the work done to crumple the cars. So W = K_i - Kf = [1/2 (540)(22.2)^2 + 1/2(1400)(-22.2)^2] - 1/2(1940)(-9.84)^ 2 = 384110 J At...

$$d\tau = \sqrt{-g_{\mu v}\frac{dx^{\mu}}{d\lambda} \frac{dx^{v}}{d \lambda}} d \lambda $$ Calling ##d \lambda = d t##, t is coordinate time in an inertial frame. $$\Delta \tau = \int \sqrt{-(-1+v^2/c^2)} dt$$ $$\Delta \tau \approx \Delta t - \frac{g^2*\Delta t^2}{6c^2}$$ where $$\Delta t = 2...

Summary:: Please see the picture below Let say: ##W_1## is weight of ##m_1## ##W_2## is weight of ##m_2## ##f_1## is friction on ##m_1## ##f_2## is friction on ##m_2## I want to find the acceleration of the system. Since I don't know in which direction they will move, I just assume ##m_1##...

I am trying to derive the tangential acceleration of a particle. We have tangential velocity, radius and angular velocity. $$v_{tangential}= \omega r$$ then by multiplication rule, $$\dot v_{tangential} = a_{tangential} = \dot \omega r + \omega \dot r$$ and $$a_{tangential} = \ddot \theta r +...

##ω = \frac {k} {\sqrt{φ}}## What is the angle between acceleration and velocity after 1spin (2π radians)? First I decided to find out what is the angular acceleration: ##α = \frac {dω} {dt} = \frac {dω} {dt} \frac {dφ} {dφ} = \frac {dω} {dφ} ω \implies ##after integrating ##\implies α = -...

The answer here is A What i did is getting the area as follows, 2×4×1/2 +3×-6×1/2 +4×-6 = -29 and then use this Δω=ωf-ωi -29=ωf-5 ωf=24 but there is no such choice.

for c) i need help d) Given: Let [forward] be positive. F 1 = — 250 N F 2 = 360 N Unknown: a = ? Equation: F net= F1+ F2 F net= m a Solve: F net= (— 250 N) + 360 N = 110 N F net= m a a = F net/ m = 110 N / 220 kg= 0.5 m/s [forward] Statement: The acceleration of the boat is 0.5 m/s [forward].

Hello all, I just joined this group after stumbling over a post from 2003 on this topic. The issue I'd like to deal with is the spinning bucket of water and why the water will still climb up the sides of the bucket if the bucket is stationary. In the original post an Absolutist put it like...

I am thinking of using ΣF = m.a to find the acceleration but I don't know what causes the resultant force to the right. I thought it will be the difference in pressure on the left and right leg of the U-pipe (picture on the right), which is ΔP = ρ.g.h but the force (ΔP . A) won't be directed to...

Suppose a particle is moving around a circular track of radius R at speed v. To bend around a circle some agency has to exert an acceleration towards the center of the circle. I analyze the forces acting on the particle, its weight and the normal force and there is no acceleration in the...

Fully ionized gas, if compressed to a cylinder of mm scale, collapses rapidly and accelerates the e/ions to very high energies (MeV). The temperature in the compressed gas is around 100 eV. What could be the possible acceleration mechanism?

Hi, I'm struggling to start this exercice, where I have an inclined air hockey table with an angle alpha. They gave me this chronophotography (this is online) saying that the ratio is 1:1 I really don't know how to proceed since this is online and I'm thinking if I measure this with a ruler...

Using Newton's second law, $$ cos\left( \frac{\pi}{6} \right) m(a+g) = 150 \Leftrightarrow a = \frac{\frac{2\times 150 }{\sqrt{3}}-mg}{m} =4.633. $$ Unfortunately, the possible answers are A. 1.025, B. 0.625, C. 3.75, D. 2.75, E. 1.75, F. 0. What am I getting wrong? Isn't the force exerted on...

First I determined the direction the masses will be traveling by comparing the change in potential energy, so when M2 rises by Δy, M1 drops by Δy. Potential energy decreases when M1 drops and M2 goes up. Tension force for string pulling against M1= 400 x gsin30°, and since there are two strings...

This derivation is found in Kleppner's mechanics book. It shows how to find the acceleration in rotating coordinates by differentiating ##\vec v_{in}=\vec v_{rot}+\vec\Omega\times\vec r##; subscripts IN and ROT stand for inertial and rotation respectively. My question is what the term...

This looks like a classical setup but I can't find a solution. We can calculate the energy of the system by looking at the work done by the gravity and the spring. But how do we divide the energy between the kinetic energy of the pulley and the rotation of the pulley?

A stationary observer sees a particle moving north at velocity v very close to the speed of light. Then the observer accelerates eastward to velocity v. What is its new total velocity of the particle toward the north-west relative to the observer? I ask because while the particles total...

I want to create a method to calculate acceleration of blobs in any degree pendulum (double, triple and more). I have this equation but I am not sure if it is correct, or how to extract acceleration from it. [Mentor Note -- this is a new thread start to correct errors in the previous 2 thread...

(a) No, a person seated inside the train compartment will not be able to tell whether the train is accelerating on a horizontal track or moving uniformly up an inclined track by observing the plumb line. (b) I am assuming that both observers are not allowed to look "out" of the boundaries of...

So I first tried to find L using torque, Torque=d/dt*L, and took the integral of this. Ended up with 23.28484t Now I square the equation L=rotation rate*I to get L^2=rotation acceleration *I^2 Angular acceleration=L^2/I^2 I feel like I am doing something wrong though, this doesn't give the...

I know its something to do with my unit conversions because my answer is the right numbers but too small by a factor of 10000. I convert the radius to meters by multiplying it by 1000. I convert the density to kg/m^3 by dividing it by 10. I find the volume using the equation (4/3)*pi*radius^3...

##\tau## = 0.5*mg ##\alpha##= (0.5mg)/##mr^2## This is what I'm finding difficult to understand, if a particle is in linear translation, how can it have angular acceleration. If by calculation, angular acceleration is non-zero, then shouldn't the body must move in a circular path with...

I'm trying to simulate the physics of a Toyota Camry during acceleration with a time granularity of 100ms. My simulated conditions are as follows: m = 1590 kg v = 17 m/s a = 1.5 m/s2 η (transmission efficiency) = 0.85 rwheel = 0.35 m Fdrag = 100 N Ffriction = 260 N Faccel = 1590 kg × 1.5 m/s2 =...

(a) Using COE, $$mgh = 0.5mv^2 + 0.5I\omega^2$$ I solved it, where $$\omega = 112 rad/s$$ (b) This is the part where I have question or problem. I saw my course mate working and he start of with finding centripetal acceleration. $$a_c = \frac{v^2}{r} = \frac{(r_0\omega)^2}{R_0}$$ Why isn't it...

So the teacher said that acceleration was the rate of change for velocity so in 3 minutes the velocity of the election needs to go to 200m/s so i used the formula and I found that every minute the electron needs to accelerate at 66.7m/s2 to reach 200m/s in 3 minutes and for each second it...

Like I said, objects with the higher acceleration are giving me the lowest values. For a hoop, I got I=0.1*MR^2 For a cylinder, I got I=0.7*MR^2 this seems backwards, no?

Okay so I actually have the answer because my teacher basically just gave it to me, but I would really like to know why I was even wrong in the first place. Here's my steps: 1. Knowing the momentum transfer per unit area is described by: 1/A dp/dt = S/c. I can begin by relating some known...