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Questions tagged [free-fall]

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Which way would objects, inside a container falling through earth's atmosphere, move, relative to the container?

Say, a sealed hollow container with 1 atm air pressure inside, is falling through earth's atmosphere. It is falling steadily with one side always facing the ground (Front Side) Inside the container, ...
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Can a person free fall onto a big block of jelly and survive disregarding the eventual suffocation? [closed]

Assuming the height is sufficient enough to achieve terminal velocity how high should the block of soft jelly be to dissipate the impact energy safely for an average human?
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Pressure on the outer hull of aeroplane on theoretical emergency landing

I'm trying to figure out the proper way to calculate the pressure on the hull of aeroplane when landing on water. Let's say the horizontal velocity of plane is $1000$ km/h and it starts free-falling ...
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4answers
131 views

Jumping from a tall building with a chair [closed]

Warning: Don't try this at home! I saw a memeish post that when your building is on fire and you're in a high floor then take a chair, tie some weights which are heavier than you to the chair and ...
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Falling from a high cliff [closed]

I've always wondered about the reason why falling from a high cliff could actually cause death, is it the normal force exerted back from the ground? or is it related to energy? or what? thnx.
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Schrödinger Equation for a freely falling body near the surface of Earth

Near Earth's surface the Schrödinger equation of a freely falling particle takes the form, $$ \frac {-\hbar^2}{2m} \frac {d^2 \psi (y)}{dy^2} + mgy\psi (y) = E \psi (y). $$ Putting $k=\frac {\sqrt {...
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Mass hanging from spring in free fall

Q: A mass $m$ hangs from a massless spring connected to the roof of a box of mass $M$. When the box is held stationary, the mass-spring system oscillates vertically with angular frequency $\omega$. If ...
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Ball dropped from building question

So in one of my physics books, under the free fall section, it was written A ball is dropped from a building of height $h$, speed $u=0$ and it reached ground after time $t$. From the same ...
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Constant gravitational acceleration $g$ and energy

I've been taught that $g$ is constant for different masses and that if I were to drop a heavy object and a light object from the same height then they would reach the ground at the same instant with ...
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2answers
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How to change a formula when changing the axis?

I have been lerning about acceleration and free fall recently, and we were told the formula for distance is $s=s_0+v_0t+\frac {1}{2}at^2$ (for movement along $x$-axis) but when we change the axis (to ...
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1answer
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Does mass slow down an object falling through the atmosphere? [duplicate]

If I throw two objects with the exact same shape and size, but one of them is heavier, will they arrive at the same time? We learn in basic Newtonian physics that mass doesn't influence the speed in ...
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Equations of motion due to gravity [duplicate]

This question has probably been asked before, but I couldn't immediately find anything with a search. Two masses of $m_1$ and $m_2$ kgs are in space separated by a distance of $x$ meters. They now ...
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2answers
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If you fell into a black whole with an accretion disc, but perpendicular

If you fell into a black whole with an accretion disc, but orthogonal to the plane of the disc - would you ever meet the disc? I'm not asking whether you survive long enough, and obviously we assume ...
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1answer
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Falling object and the side wind

I don't have a big knowledge on Physics so I'm sorry in advance if it doesn't make sense.. If a brick is falling from 100m tall-building when there's the side wind of 30m/s, is there any way I can ...
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1answer
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Stability of a falling object

Suppose there is a falling object that has flaps around it providing resistance to the non-contact force of gravity. How would the vehicle theoretically not flip over? From my understanding, the ...
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1answer
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Why mass has no effect on free-fall acceleration? [duplicate]

I learned that mass is a property of objects that specifies how much resistance an object exhibits to accelerate. So, pushing an object with a greater mass would cause a smaller acceleration than ...
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1answer
120 views

Initial acceleration concerning free fall

I'm in the process of conducting research concerning free fall with air resistence. I'm dropping a beach ball filled with air from certain heigts, while measuring its speed and acceleration during the ...
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1answer
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A question on an elevator and the measurement of $g$?

Imaging a person in an elevator accelarating towards earth with accelaration $a$. At some point the person let a ball fall from his hand. Does the time that ball needs to hit floor equal time that ...
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1answer
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Why is ʻOumuamua traveling so slowly?

Imagine a space rock that starts at rest at the Lagrange point between the sun and our nearest stellar neighbor, Alpha Centauri. That would put it at about 2 light years away from the sun. Now, it ...
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Does free fall ever occur on the surface of Earth?

According to the definition of "Free fall", which is "Downward movement under the force of gravity only.", free fall only occurs when gravity is the only force acting on an object. But here on Earth, ...
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The dropping of two identical balls without air resistance [closed]

I was thinking about this and couldn't really figure it out. You are standing on a cliff and you have two identical balls. In this case, air resistance is to be ignored. The only thing different is ...
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3answers
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Falling - is the gain in KE linear? [closed]

When a ball falls from a high place, it experiences a gravitational force. Forces make objects accelerate (in this case, it is constantly increasing the velocity). Because $KE = \frac{1}{2}mv^2$ this ...
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Why free-fall acceleration is considered constant rather than increasing? [duplicate]

The force acting on a body of mass $m$ is $mg$, where $g$ is acceleration of free fall ! But why should there be a #uniform acceleration of free-fall in the first place? As per Newton's universal law ...
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Free-Fall time of a collapsing Star (Spherical Symmetry/No Rotation/Classical Mechanics) [closed]

I have been trying to prove the free-fall time $(\tau_\text{ff})$ of a collapsing star, which is the time it would take a star to collapse due to gravity, in the absence of pressure or other ...
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1answer
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The maths of free fall and near free fall [closed]

I saw Usain Bolt's video today and the source said that they were in a near free fall (Usain bolt races in reduced gravity) The question that came up to my mind is how the math works regarding free ...
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1answer
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Free fall in a centrifugal space ship?

I have read the basics on O'Neil cylinders. A tube with a five mile diameter rotating almost 23 times an hour would produce forces akin to earthlike gravity at the rim. There would be a space in the ...
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1answer
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From Rest to Final Velocity (Free -Falling Physics Problem)

I am notorious for over thinking and I am having a problem with this question: On another planet, a marble is released from rest at the top of a high cliff. It falls 4.00 m in the first 1 s of its ...
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1answer
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Falling towards black hole with lorentz factor

Falling at rest from infinity to black hole. I calculated the velocity when an object fall from infinity to a black hole or vicinity of one. $c\Big(1-\frac{2GM}{c^2r}\Big)\sqrt{\Big(\frac{2GM}{c^2r}\...
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2answers
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Question about the Normal Force exerted by Planet Earth in relation to centripetal force

I have the following question based on a paragraph from my Physics textbook (I am translating, so the result might not be the most elegant): It states that due to the centripetal force resulting from ...
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1answer
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If a body experiences air resistance while falling can we say that it is in free fall?

We know that free fall is when an object is acted upon by only gravity. But in practical cases, air resistance acts on every object that is falling from a height. So can we call their motion as free ...
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1answer
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Is projectile motion a free fall motion? Is the vice versa also true?

We know that in ideal case a projectile will be acted upon by only the gravitational force and hence can it be considered a free fall motion? An object dropped from a height will be under free fall ...
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1answer
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If I jump from space using a spacesuit filled with hydrogen could I survive the fall? [closed]

If I fill a spacesuit to its maximum volume with hydrogen while wearing it (who cares about the breathing part anyway) and jump from space (let's say, from 100km above sea level, a.k.a. Karman Line), ...
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3answers
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Free fall - equation - what am I doing wrong? [closed]

I have a very simple question: I want to derive the distance an object is falling in free fall. I know there are several derivations regarding this on the web. However, I tried a different approach ...
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2answers
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Relativistic equation for motion in a constant acceleration

I found many questions regarding relativistic velocity addition and the relative formula $$V_{x} = \cfrac {V_{x}^{'} + v}{1+\cfrac{vV_{x}^{'}}{c^{2}}}$$ but I found none concerning velocity ...
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2answers
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Why do 2 bodies of different masses reach the ground at the same time? [duplicate]

Since inertia is the quantity that resists change in motion, and is represented by mass, and if two different objects are dropped from the same height, shouldn't the heavier mass accelerate less than ...
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4answers
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Why are non-equally heavy objects falling at the same speed on the moon? [duplicate]

This is no duplicate. I have own questions to it, that I want to have explained. I recently read about this thing Galileo discovered with severel experiments. Everything, with any mass, falls at the ...
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2answers
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Why must the worldline for a freely-falling body be straight?

If spacetime were on an xy graph, the x-axis being time and the y-axis being space, an object that is in interstellar space with no noticeable gravitational influences on it will have a worldline that ...
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How does vertical deformation of an object soften the free fall of a body?

I'm a bit confused about the situation in this exercise: A man fell off a building of height $h$, with null initial velocity, but he survived thanks to a metal box that softened the fall deforming ...
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Reason for body attached to a string being in free fall?

This is a question I found in a book: A string is wrapped around a uniform cylinder as shown in diagram. When cylinder is released string unwraps without any slipping and the cylinder comes down. ...
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3answers
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Fictitious force on a free falling body?

So I have read the first answer to this question and I have trouble making sense of the "Newton's explanation" part. If a person was inside a car moving on a straight road with acceleration of $9.8ms^...
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3answers
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Does acceleration in free fall disprove Newtonian mechanics? [duplicate]

In Newtonian mechanics, how come the net force on an object in free fall is zero, yet it is accelerating?? If F=(a)(m), and F=0, it follows that: a must equals 0 But in reality a falling object will ...
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2answers
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Calculating Intitial Position given the ratio between the last two seconds of free fall for 1D motion

I've tried this problem in multiple different ways and can't seem to come up with an acceptable answer. The question is, A rock is dropped from the top of a tall building. The rock's displacement ...
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How to Lift an object at constant velocity vertically

Let's say there is a Table on the floor . I lift the table up in such a way that it keeps going upwards 5 m/s (I kept holding the table every instant). I lifted the table for 3 seconds so it reached ...
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1answer
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When an object is in free fall from rest at an infinite radius, is its potential energy proportional to its clock rate?

The total energy $E$ of an object in free fall from rest at an infinite radius is known to be $$ E = m c^2 $$ As the object falls, its energy doesn't change since the object is merely moving freely ...
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1answer
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Finding displacement of a body in freefall for an unknown time [closed]

A brick is dropped from a building. After some time, the brick falls 40 meters in one second. Find how far the brick travels in the next second. My intuition for this problem is to use two ...
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If a bullet is shot up in the air off a cliff, will the final velocity be greater?

Since acceleration due to gravity is 9.80m/s^2 wouldn't the final velocity keep increasing by 9.80m/s each second that the bullet is in the air since velocity has a time dependence? If that is the ...
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1answer
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Free fall on a planet using General Relativity [closed]

There is an object in free fall above the surface of some planet. This planet has no significant atmosphere so there is no significant air resistance on the object. Also there is no significant ...
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3answers
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Force on falling objects (in Earth)

Will a object falling from a height $x$ above the surface experience the same impact as another object falling In a hole of depth $x$ from the surface?
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1answer
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How can cats survive a 32 floor fall? [closed]

There have been instances where cats fall from more than 30 stories high, yet escape alive! The record was a cat which fell 32 floors, yet only suffered only slight damage to its body and lost a ...
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1answer
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Why is normal contact force acting on a person in an elevator during a free fall 0? [duplicate]

Since normal contact force between two surfaces depends on molecular interaction between them, then why does its value change with the acceleration of the elevator?