Questions tagged [acceleration]

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

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Friedmann Expansion

I have a strange question that I can visualize but not find anything to really answer my query. The Newtonian law states that something in motion tends to remain in motion. We all know about ...
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Does Horizontal Velocity remain constant when it hits a surface in a Parabolic Motion?

It is told in one of the answers that the horizontal velocity stays at 4.0 m/s after the ball bounces from the plate. Why is it still at 4.0m/s, isn't there friction or is it neglected for the sake ...
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Why isn't acceleration always zero whenever velocity is zero, such as the moment a ball bounces off a wall? [duplicate]

The answer to this homework problem is $\left(\text{D}\right) :$ I understand why we rule out options $\left(\text{A}\right)$ and $\left(\text{B}\right)$ first. However, I don't get why $\left(\...
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Acceleration-time graph

1) At first, the acceleration opposes the direction of velocity and the object must be slowing down. 2) At t=4, is the object’s velocity would have been at rest if the acceleration changed to 1.5 m/...
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Force and center of mass acceleration

https://i.stack.imgur.com/3w7Mt.png I have a rod with mass $m$. Above are two ways I can apply a perpendicular force to the rod. Since the mass of the rod is uniform, its center of mass is in the ...
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Does a black hole have thrust? Could they be acting as galactic engines? [closed]

I identify four possible kinds of thrust below (there may be more or less). I don't know how to do the math to test them though. Direct transfer of kinetic energy as thrust. The energy of objects ...
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If you were to push a block in space in an ideal vacuum scenario with zero friction, what would be the final velocity of that object

Say you push an object with 10 N force(just once and let it go) of mass 10kg object in space with zero friction and nothing in the way of its path. What would be the velocity of that object? I would ...
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Does an classical charge that is stationary in a gravitational field radiate?

The well known Larmor formula tells us that an accelerated classical charge radiates a power proportional to the square of the acceleration. It has been shown that a charge in free fall in a ...
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If an object with more mass experiences a greater gravitational force, why don't more massive objects fall faster? [duplicate]

According to Sir Isaac Newton, the gravity equation runs like this: $$ F = \frac{Gm_1m_2}{r^2} $$ where $F$ is the gravitational force, $G$ the gravitational constant, $m_1$ and $m_2$ are the ...
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Moment of Inertia Race [closed]

Wikipedia shows an example of how to the moment of inertia determines how fast a rotating object rolls down an incline plane. the race Includes: spherical shell, solid sphere, cylindrical ring. solid ...
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Find the time when tangential acceleration is equal to radial acceleration [closed]

A particle begins to move along a circular path of radius R with a constant magnitude tangential acceleration of $a_t$. After time $t$ it's the centripetal acceleration is equal in magnitude to ...
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Do “light” and “heavy” objects still accelerate at the same rate at near light speeds?

My (very poor) layman's understanding of physics is that as something approaches c, it has a relativistic mass that is a combination of its actual mass and velocity. Do this affect its acceleration ...
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Acceleration of two bodies on an incline and the normal between them [closed]

Question: What is the acceleration of each body, if they slip along the incline? What is the normal between them? Assume the incline to be frictionless and neglect air resistance. My teacher solved ...
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Calculate speed of an object using angle and time [closed]

I haven't had any physics class or anything close to that in a long time, and I'm currently confronted with an exercise I don't remember the formula(s) to solve it. Assuming I have an object of ...
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Is it speed or acceleration that leads to time dilation? [duplicate]

Is it acceleration or speed that leads to time dilation or both? For example, when a spaceship accelerated to (almost) the speed of light, then reversed course to come back towards earth, does this ...
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Why does mass cause resistance to acceleration?

If I were in a vacuum with no gravity or friction, why would it be harder to push a floating bowling ball than a marble? Is there anything happening on an subatomic level that makes matter act ...
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why a car with very high speed topples away from the center of turning when it is cornering? [duplicate]

If a car is turning to the right with very high speed, why the car will topple to the left and cause an accident?
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Convert inertia formula to excel calculator

I've been looking at this question: "Weight" of moving object in a car collision but to be honest I can't get my head around how to work it out myself (I'm not a physics student!). What ...
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Using two simple pendulums to estimate $g$

I know that using the period expression for a simple pendulum we can have an estimation of the acceleration of gravity $g$. I encountered the following question One way of measuring the terrestrial ...
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When will a person falling into a black hole be crashed by tidal forces?

Assume that a person can resist $30g\approx 300\frac m{s^2}$ (remark: the record is actually at 46.2). I want to solve for the distance $r$ at which a $1.5m$ tall slim person falling radially into a ...
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Why alternating current produces electromagnetic waves? [duplicate]

So my question is: why alternating current produces electromagnetic waves? There are plenty of answers on google that state it as fact, but none answer why. I mean what is it about accelerating ...
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maximal acceleration of a wheel-driven vehicle

I was thinking about the maximal acceleration of a bicycle, I found a similar question. What remains unclear is that I found two coefficients of friction, one for rolling and one for static friction. ...
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How does centripetal acceleration have direction/vector and magnitude while in the formula $v^2=v\cdot v$ is scalar?

$$a_c=v^2/r$$ 1. How does centripetal acceleration have direction or vector while in the formula dot product between velocity vector is scalar (as in kinetic energy)? Radius is scalar quantity. What ...
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Force during collision would be very high, would it cause a very big damage? [closed]

So suppose a body of mass 10kg travelling at 5m/s crashes into a wall, the time of deceleration would be very minute, say 0.01 second, then the magnitude of deceleration would be $$\frac {0-5}{0.01} ...
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Regarding Goldstein's claim that $\mathbf{F} = \dot{\mathbf{p}}$

From Goldstein: ... The mechanics of the particle is contained in Newton's second law of motion, which states that there exist frames of reference in which the motion of the particle is described ...
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In the equation for acceleration (with known $v$, $u$ and $s$) why velocity is squared and displacement is multiplied by 2? [closed]

In the following equation $$a = \frac{v^2 − u^2 } {2s} ,$$ where $v$ is the final velocity, $u$ is the initial velocity, and $s$ is displacement. Why is velocity squared and displacement multiplied by ...
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Could a rover drive to orbital velocity?

Could a rover, assuming it is on a perfectly smooth sphere in space, eventually reach orbital velocity? Would there be a limit on the possibile speed?
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Intuition for formula of tangential component of acceleration in general curvillinear motion

In certain problems of plane motion, the position of the particle P is defined by its polar coordinates $r$ and $\theta$. It is then convenient to resolve the velocity and acceleration of the particle ...
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Reaching 99.9% of the speed of light $c$ at 1G acceleration [duplicate]

If an object in space accelerated at $9.8$ms$^{-2}$ constantly, and no other forces were experienced, how long would it take for the object to reach the $99.9\%$ of the speed of light $c$.
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Confusion on Horizontal & Vertical Components of a Parabolic Motion

This was a question I found about projectile motion, the question was what's the bike's speed when it took off. Using $S=ut + 0.5at^2$, the time taken to reach the ground is $0.505 s$, they used ...
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Why $g$ on equator is less than $g$ on poles? [duplicate]

I found this on my physics book. The book says $g$ on equator 9.78 $m/s^2$ and on the poles 9.81 $m/s^2$. Is it due to gravity?
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Deriving the equality between the external torque and the rate of change of angular momentum, for a system of particles

I've started working through Analytical Mechanics for Relativity and Quantum Mechanics by Oliver Johns and I'm stuck on deriving a formula. In the section titled "Change of Angular Momentum", Johns ...
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When a body completes one revolution around a circular path will its acceleration be 0?

When a body is moving in a circular motion the acceleration keeps changing, will it be zero when it comes back to the same point it started from(will the average acceleration be 0?)
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The maximum velocity of an object in water [closed]

Suppose we have the mass and volume of an object, like a sphere, with density less than water. We grab it under the water and leave it, so it will fly up to the surface. What will be the maximum ...
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Acceleration as the second derivative of displacement function

Let $x$ be displacement as a function of time $t$ and some other physical quantity $k$ such that $ x = f(t,k) $ Now, 1) Will the acceleration $a$ be $\frac{\partial^2 x}{\partial t^2}$ or $\frac{d^...
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Definition of gravitational field strength

The definition of gravitational field strength states: gravitational field strength is the force experienced per unit mass by a small test mass at a point in gravitational field. It can be given as $g ...
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Is it true that when you accelerate due to a non-gravitational interaction gravity is pulling you in the direction opposite to the acceleration?

We don't feel acceleration when we are only in a gravitational field due to equivalence principle as I understand it says gravity is simply inertia in spacetime. Is there any other type of force ...
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Does the Jerk (derivative of acceleration) play a significant role in relativity?

In particular, I'm thinking of spaghettification that occurs as an object falls into a black hole (as an extreme example). But what about tidal forces like the tidal heating taking place on Jovian ...
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How is rest mass $m_0$ in $E=m_0c^2$ related to mass $m$ in $F=ma$?

A particle at rest has energy given by $$E=m_0c^2$$ where $m_0$ is defined as its rest mass. So rest mass is essentially a measurement of a particle's intrinsic amount of potential energy. How is ...
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Vectors (with reference to a pendulum)

Why is the acceleration of a pendulum non-zero at its lowest point?
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Centripetal acceleration of Centre of mass of rolling body

Does the centre of mass of body rolling on a stationary floor experience centripetal acceleration downwards towards the IAOR (instantaneous axis of rotation) which here is the point of contact of body ...
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'Why don't electrons accelerate in a circuit' Confusion

https://physics.stackexchange.com/a/18806 Apparently he said 'at the same time', so when the electrons are 'pushed' by the electric field it is 'blocked' by the resistance simultaneously, if he said ...
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Does the proper four-acceleration $A^{\mu} = (0,0)?$

Let the proper four-position vector $x^{\mu}(\tau) = (0, \tau)$. Differentiating this successively wrt $\tau$ I get the four-velocity $u^{\mu}(\tau) = (0, 1)$ and then the four-acceleration $A^{\mu}(\...
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Human Body Upward Acceleration on Scale [closed]

I am reviewing for a Physics exam, and have come across the following example question: If I weigh 200 pounds, but a scale I'm standing on reads 400 pounds, then I am accelerating upward at 1g 2g 3g ...
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Rotational analogue of Newton's 2nd law

If we are writing torque equation about general point what points must be taken into account for getting the correct result. Also If that general point is accelerated then how do we deal with this. ...
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Acceleration of The Centre of Mass of A Rod

The acceleration a of the center of mass of a system is equal to F/M, where F is the net external force and M is the total mass of all the particles of the system, or at least that is my current ...
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Do variations of the Earth's magnetic field affect gravitational acceleration at Earth's surface, and if yes, by how much?

The Earth's magnetic field varies with time over geological time scales (we have phenomena such as pole inversion). Can this affect the acceleration of gravity at Earth's surface? I would think that ...
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What would happen if I used a jet pack that accelerates at $g$ but always upward?

I'm trying to imagine what would happens if gravity is cancelled. I assume that without air, if the effect of gravity were to disappear I would fly off Earth on a tangential line. But with the air ...
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Does a charge in a gravitational field make a magnetic field?

I know that general relativity unifies the electric charge with the magnetic field via relative motion. So if I accelerate a charge then anyone in another inertial frame will see a magnetic field. ...
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How and why does momentum get transferred? [closed]

Let us imagine an isolated system and there are two objects of whatever masses and size. Let one object move towards the other object with constant velocity. We know, that when they collide, the ...