Questions tagged [free-fall]

Free fall is any motion of a body where gravity is the only force acting upon it. In general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it.

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"Outrunning pressure": Liquid in free-fall

I've checked out related questions and didn't see an answer to my question. Scenario: Liquid in open-top container, together accelerating downward with magnitude $g$. It was straightforward for me to ...
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Free fall with $g$ not constant [closed]

An object is falling down to earth and air resistance is ignored. The starting velocity is 0. The distance between earth center and the objects center is "l". Normally you say g=9.81m/s^2 ...
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If I dropped a golf ball straight down from about 5 meters, would air resistance cause a noticable change in the acceleration of the ball?

I am working on a Grade 11 physics lab report. I dropped a golf ball from a balcony 5m and 13cm off the ground. When I did all the calculations, the acceleration was 7,72m/s (calculations below). I am ...
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Speed of falling objects / with different altitudes

I have a question about gravity So as we know gravity is significantly less on high mountains or tall buildings and increases as we lose height ☕ My question is that if we have 2 objects with the same ...
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Significance of time being dependent in many equations for gravity?

I have noticed, when browsing the equations for a falling body, it is often the case that distance is the independent variable rather than time. Take for instance, the time $t$ taken for an object to ...
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Non-parallel magnetic dipole falling throug copper tube

What happens with magnetic dipole while falling through copper cylinder? If it's parallel to z-axis (shown on picture below with red color) we know that it stays parallel to the z-axis all the way ...
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Force components on dipole falling through copper ring

We have a magentic dipole parallel with z-axis (shown on the diagram below) falling through copper loop, because of changing magnetic flux there is induced current in cooper ring/loop and consequently ...
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Magnet falling in copper tube, radial force component

Consider a Dipole magnet falling through infinite copper pipe. If we displace a magnet a little bit so that the dipole isn't pointing to the same way as pipe (dipole isn't parallel to the pipe) we get ...
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Times of free-fall in different inertial reference frames in classical physics

Imagine that a ball is thrown directly down at a rate of 20 m/s from a height of 100m in Earth's gravitational field. If we were to calculate the time it takes to fall we could use the kinematic ...
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Why the Earth's gravitational acceleration is the same for every body? [duplicate]

As i understand forces gives bodys acceleration. And mass resist this acceleration. So why does every body, regardless of their mass, gains the same acceleration when they are in earths gravitational ...
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Proper Time of Fall in Schwarschild Metric

I've been trying to understand how the proper time of a radial fall into a black hole is finite, but I'm confused because I found many results and they do not seem to be the same. Usually what I see ...
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Inertial to Gravitational Mass Ratio

According to Galileo's discovery the objects fall at the same rate due to the equality of inertial and gravitational masses. Where in our universe these two would not be equal? Following the question,...
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The value of $g$ in free fall motion on earth [closed]

When we release a heavy body from a height to earth. We get the value of $g=9.8 \ ms^{-2}$. Now, I'm confused about what it means. For example, does it mean that the body's speed increases to $9.8$ ...
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Free falling bodies in the absence of external forces

We know that if two balls $B_{1}$ and $B_{2}$ having masses $m_{1}$ and $m_{2}$ respectively and suppose $m_{1}$ is sufficient greater than $m_{2}$. In daily life observation, we see that both the ...
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Behavior of a loose coin on a free fall ride

At Six Flags over Texas, there used to be a free-fall drop ride called "the cliffhanger". Simply put, you got into a metal box, got elevated up to about 75 feet or so, and got dropped ...
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An object falling from very far would have varying acceleration, how can that be accounted for?

I want to have a function that describes where a falling object is. Like this one: h(t) = -g*t²/2 But this one is for the usual close to the surface case, where there is no variation of gravity due to ...
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Shock testing equations (oversimplified?)

I'm designing a shock test tower with a maximum drop height of 1.8m. I'm adding bungee cords to add impulse and reach the intended 150G as it hits the programmer at the bottom. My question is, is it ...
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Falling stones attached by a string

Suppose we have two stones, one "big" (A) and one "small" (B), the smaller one over the big one at the moment of free fall. Suppose also that a string of a certain length is ...
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Solving and Graphing Differential Equations in Falling Motion with Resistance

In a fall motion with resistance, when the terminal velocity is greater than the initial velocity and when the terminal velocity is less than the initial velocity, the equation for solving the ...
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Free Fall and constant acceleration

Although the acceleration of free fall is constant, why don't the distance go like $y = 9.8+4.9= 14.7m$ after 2 seconds, $y= 19.6+14.7 = 34.3m$ after 3 seconds? I think Constant acceleration work like ...
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Motion of free fall [duplicate]

We know that according to law of free falls object, all bodies fall with the same constant acceleration. But in distance formula ($s = \frac12 gt^2$), why the acceleration is just half?
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Is the acceleration of a falling object constant? Explain [duplicate]

My name is kakari john I come from wiawso
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What would happen if when falling down you get pushed up?

I know it will be a weird question, but im not a physics well informed person and I had this unsolved question for long time. What would happen if lets say you are falling with someone else from ...
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Electromagnetism as curvature of space-time? [duplicate]

If gravity can be expressed as a curvature of spacetime, can electromagnetism similarly be expressed as curvature on higher dimensions of spacetime? Also (I'm not sure if the 2 questions are linked), ...
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Free Fall with non-constant acceleration due to gravity [duplicate]

In a free fall motion, the height of the falling object is constantly changing and its acceleration due to gravity is also changing. However, we usually ignore the effects of changes in height on the ...
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Gravitational collision [duplicate]

Two point particles of exactly the same m = mass 1kg is separated by a distance of d = 4m. After how much time, they will collide with each other due to the force of gravity? Assume that, the ...
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Is there a bug in this step (and how to fix it?)

Reading an old book of classical mechanics (Spiegel's theoretical mechanics) I came across a passage that I would like to clarify. In order to find the equations of motion of free falling point ...
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Free Fall time in General Relativity

Suppose you are working with the Schwarzschild metric in GR. $$ -c^2 \mathrm d \tau ^2 = -c^2 \left (1 - \frac{2 G M}{c^2 r} \right) \mathrm d t^2 + \left (1 - \frac{2 G M}{c^2 r} \right)^{-1} \...
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How can we conduct experiments to verify formulas without special equipment? How was it done in the past?

If we wanted to verify experimentally/empirically as laymen without special instruments a formula such as $s=16t^2$ which is used to approximate the distance s, in feet, that an object falls freely ...
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Differential equation of the free falling object with air resistance

I'm puzzled by the result I get when I try to solve the differential equation for an object that is falling subject to air resistance. Suppose the $y$-axis is directed upwards, then $\vec{F_a}=bv \hat{...
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A ball is dropped from a height of 1m above the ground.What will be the instantaneous speed of the ball when it is exactly at 1/2 mark? [closed]

I saw this question in this video Instantaneous speed (differentiation) by Don't Memorize In the video, the instantaneous speed of the ball is given as 100cm/sec which is equal to 1m/sec but when I ...
2 votes
4 answers
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Height of a table: what's the uncertainty?

I would like to introduce high school students to error analysis with a simple experiment: find $g\pm \Delta g$ by measuring the time a ball takes to fall from a table, repeating many times. ...
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Doubts about work-energy theorem and negative gravitational potential energy

A ball is dropped from a certain height. The work done on the ball by the gravitational force is $$W = F \cdot h = mgh$$ and the gravitational potential energy is $$U = -mg h$$ The difference in ...
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Is there a difference in energy required to make 2 items with the same exact mass but different material travel the same distance whilst in free fall?

is there a difference in energy required to make 2 items with the same exact mass but different material travel the same distance whilst in free fall? Please answer for all cases of free fall: ...
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Why acceleration due to gravity same for two objects of different masses (neglecting air resistance)? [duplicate]

If a feather ball and bowling ball are thrown , both reach the ground at the same time. (neglecting air resistance) The reason given to this is that Both the bodies have same acceleration . My ...
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In general relativity what is the relative velocity between a fixed observer and one free-falling from a finite radius?

This question is the last missing link for me to solve my other question here. In general relativity, what is the relative velocity between an observer in free fall from a distance $r_1$ from a mass $...
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Falling to Earth from Orbit [closed]

Suppose we ascend to a height $h$ away from the surface of the earth and drop an object. High school physics tells us that it will accelerate at a speed of $9.8 \frac ms$ and will hit the ground in $\...
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How deep would a hole need to be before you could no longer hear the sound of a small object hitting the bottom?

Assuming there are no obstructions, background noises, and the bottom of the pit is just flat concrete, if the average person were to drop something like a padlock (very specific, I know) into the ...
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Rotation of a freely falling body

Suppose a straight rod with one end denser than the other is dropped from a height at an angle. Will the rod hit the ground at the same angle or will air resistance cause it to straighten and hit the ...
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Michelson-Morley interferometer in free fall

We suppose that we have a Michelson-Morley interferometer in free fall, will there be no interference: the round trip time in both arms of the interferometer is the same?
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How does a virus fall down in static air?

If we drop a virus from a height, in static air, will it fall to the ground like a lead ball, a balloon, or like a virus? How will it fall to the bottom? Like a Brownian particle? It will not float ...
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What would reach the ground first? [closed]

Hi I’m trying to get my head round this if a bowling ball and coin from the Empire State at exactly the same time what would hit the ground first I know that gravity = 9.81ms-2 but what else am I ...
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Initial speed of a released object from a moving object

For example, if a helicopter is moving upwards in constant velocity of 20 m/s and at some height an object is released from the helicopter, why does the object has an initial velocity of 20 m/s and ...
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Confusion Regarding Reaction Forces and Newton's Third Law of Motion [closed]

So I was confused about reaction forces for a LONG TIME and I have finally been able to clear some of my confusions, but the concept is still not totally clear to me. Can someone confirm whether my ...
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Free fall with sound [closed]

One of my colleagues affirm that the following problem is not solvable while I think it is. Consider a body falling from rest inside a pit/well of unknown's depth ($h$). Taking into account that the ...
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What shape the Earth would have to be for an object in free fall to follow a straight line trajectory?

I was explaining to my 8 year old daughter that objects in free fall follow an elliptical trajectory instead of the commonly believed parabolic one (source: https://www.forbes.com/sites/...
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What happens to charges when a uniform wire is accelerating due to earth's gravitational acceleration?

Let me say this in a simple way. I was just curious to know whether charges experience a pseudo accelerational force in a wire when in freefall. The charges are supposed to feel a pseudo force right? ...
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Why is wingsuit water landing without opening a parachute not a survivable event?

According to this YT video, just before this wingsuit flyer opened his parachute his speed was below 90 KPH. When you jump off a 100 foot cliff your impact velocity is around 87 KPH and people have ...
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Im confused on why did my prof. put height as -14m on this question. can someone explain? [closed]

The question is A snowball rolls off a barn roof that slopes downward at an angle of $40^\circ$ The edge of the roof is 14.0 m above the ground, and the snowball has a speed of $7.00\ \mathrm{ m/s}$ ...
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What numbers would I apply to the equation $y=y_o+v_ot+\frac 12at^2$ using this simulator?

Using a Projectile Motion Simulutator (selecting INTRO from the four choices), I set the height of the Cannon at $15 \ \text{m}$, Initial Speed = $8 \ \text{m/s}$, the bulls-eye at $13.9 \ \text{m}$. ...

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