Questions tagged [drag]

The force on a body resulting from it's motion through a fluid (gas or liquid). This force is directly opposed to the direction of travel.

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83 views

Is it true that maximum height attained by a body projected vertically upward is irrespective of mass?

For example, if I threw a 1 kg stone and a 100 kg stone vertically upward with the same velocity will they reach the same height, if yes then how?
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At what speed does air drag becomes important?

Imagine an object that wants to move at a speed $v$ trough a fluid. I was thinking that when i ride a bike, there is generally a speed at which air drag becomes a problem, but if i ride slow i does ...
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Would it be possible to create a perpetual motion machine in an environment without air, friction, or dissipation?

Perpetual motion machines don't work because as it moves, the air molecules hit it and slow it down. Friction slows it down in a similar way. If there were no forces to slow it down, could it work?
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Finding a differential equation for a simple model of a meteor entering the atmosphere

Background I am trying to model the position and velocity of a meteor as it enters the Earth's atmosphere. I derived a differential equation (which I plan to solve numerically) to model this in the ...
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Is terminal velocity applicable in the horizontal plane?

Is there a speed that object A can move at, such that object B would remain 'stuck' to the front of object A, due only to the air pressure as a factor of object A's speed? I realise that friction ...
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How to calculate drag caused by string?

An example - I throw a tennis ball with a short string hanging off one side. As the ball flies the string is dragged to the side opposite the direction of the ball's velocity vector, anchoring the ...
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How to find the initial value problem for the vertical displacement $x$ of the body? [closed]

A body of mass $m$ falling from rest under gravity experiences air resistance proportional to the square of its velocity. Write down the initial value problem for the vertical displacement $x$ of the ...
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280 views

Calculating magnetic strength required to hold an objects weight + wind speed?

Note: I'm a bit new to this subject, so I'm looking for some general answers, ballparks, and direction to continue my research. Scenario: I have three electromagnets capable of X amount of holding ...
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1answer
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Is atmospheric pressure balanced on an object as it moves?

Consider a box sliding along a friction-less floor at a constant velocity. Now typically atmospheric pressure is 14.7 psi on all surfaces of the object. But if it is moving at a constant velocity, ...
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Compression vs. Friction - what happens when space objects enter Earth's atmosphere?

When reading about what happens when cosmic debris enters the earth's atmosphere, some sources say friction, others say compression. For example: On space.com it says: Meteor showers occur when dust ...
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Relation between the hole in a semispherical parachute and the area of the parachute and drag coefficient of such parachutes

I can't seem to find much information regarding the size of the Vent (the hole). Nor can I find a concrete answer to the value of the drag coefficient, $C$. I've read in some websites that $C$ is ...
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1answer
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Is there a drag in a moving fluid due to pressure (reaction) from the walls of the tube?

Consider a tube of linearly varying cross section... Now consider a section of the tube...There are pressure on the ends of this section due to the fluid... Now consider the walls, there is a ...
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1answer
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How can you model how far a spinning cylinder will move forward during free fall?

I am a high school student and have just started calculus. Part of my project involves doing this experiment where I drop a cylinder from about 10m high with a large backspin and see how far forwards ...
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Theoretical question about velocity and acceleration

Imagine you have a ventilator that is spinning madly an creating strong air up force upwards. Then you put in the middle with a holder a paper ball. Then some-have detach the paper from holder. Sure ...
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1answer
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Motion with air resistance [closed]

How to tackle real life problems in KINMEATICS in which air drag in some way is involved? I've attached one such problem in which I was stuck.
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1answer
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How to calculate the precise displacement of an object in projectile motion?

I am curious about how to calculate the precise location of a projectile. Assuming that acceleration due to gravity is $-9.81 \text{ms}^{-2}$, how would you calculate the displacement of a tennis ball ...
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How much is a smooth sphere affected by air resistance at different spinning rates?

How to you calculate how much a smooth sphere is affected by air resistance at different spinning rates? None of the answers to How can you calculate air resistances at different speeds? answer my ...
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Work done by air resistance

How can air resistance do work on a freely falling body on earth. then it's displacement is only due to gravity. I think Air resistance doesn't displace the body falling. So what is the meaning of ...
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1answer
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Why do we use $m\frac{dv}{dy} = -b(v-v_{ter})$ while determining how the terminal velocity is changing for an object falls down in linear drag force?

Why do we use $$m\frac{dv}{dy} = -b(v-v_{ter} )$$ while determining how the terminal velocity is changing for an object falls down in linear drag force . I was Jr Taylor's classical mechanics. In the ...
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What is the structure on SUV's top back edge? [closed]

I see a lot of SUV's that has the structure as shown in the picture .I am talking about the the top back edge (right above the back window). Wont't it worsen the streamlined design and causing more ...
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1answer
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Is $b$ in the drag force formula $F=-bv$ constant for a certain medium and object?

I heard that $F=-bv$, where $F$ is the drag force, $b$ is the damping coefficient, and $v$ is the velocity of an object, can be used to calculate the drag force exerted on an object moving at a ...
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1answer
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What is the function for the magnitude of air resistance/drag?

In John Taylor's Classical Mechanics, he gives a basic treatment on air resistance/drag. In order to do this, he models air resistance as $\mathbf{f}=-f(v)\mathbf{\hat{v}}$, and then Taylor expands $f(...
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Work Done By Gravitational Force and Terminal Velocity

Using these two definitions of work: Work = Force * Distance Work = Change in a particle's kinetic energy When a skydiver hits terminal velocity, their change in kinetic energy is basically fixed ...
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How does the width or depth of a container of water affects the speed of an object (e.g. a toy boat) travelling on it?

I am planning to carry out an experiment to investigate how the distance between an object travelling on water (i.e. a toy boat) and the walls would affect its speed. I predict that the speed will ...
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Variables in calculation of drag coefficient

Okay, so I looked up drag force equation, and I found that the equation involved the drag coefficient. Then I looked up the drag coefficient, and the equation for it involved the drag force. ...
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How to calculate the elapsed time while reaching the limit speed?

(Figure drawings belong to me.) In the figure, a person falls freely from the tower at a height of $1500\ m$. When the limit reaches speed, it opens its parachute. By the way, how do we calculate the ...
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Are objects at high speeds subject to friction (in described fashion)?

https://www.youtube.com/watch?v=1NnyVc8r2SM In this video quicksilver moves plastic bullet's with his finger from a different time reference. Needless to say, if bullets were in contact with an ...
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Moving a marble in a maze using wind force

For a school assignment, I have to write a game where you can move a ball through a maze by generating unidirectional wind when the mouse is clicked. The ball is on a flat surface. The concept is ...
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Two spheres falling through a pipe

Imagine a pipe of radius $a$ perpendicular to the ground. A liquid flows in the pipe. Now you throw (instantaneously) two balls with radius $b$ (where $b << a$) through the pipe: one through the ...
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Does weight affect the drag force on a falling parachute?

In my physics class we currently have to do research about a motion and preform an experiment and write an essay on it. The idea I had was to drop two parachutes with different areas from the same ...
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Air drag on a projectile [closed]

A projectile moving through two spatial dimensions has a resolution of two velocities, $$\vec i(V_{0}\cos\theta)+\vec j(V_0\sin\theta -gt)$$ each of which should have their own air drag(?) But also ...
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Drag - Dimensional Analysis / Buckingham $\pi$

I'm working on dimensional analysis and I'm having trouble. Here's a problem from my book I'm working on. I'm supposed to consider a small sphere experiencing acceleration due to gravity $g$. The ...
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Non-inertial uniform velocity frame

Suppose, an observer is on a train which has only platform to stand but no walls. The train is moving with a constant velocity with reference to railroad. While moving, the observer feels strong wind ...
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1answer
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How would the air pressure inside the hyper loop affect the acceleration of the cabin?

I would like to ask a question about hyperloop's inner air pressure, how would air pressure inside the semi-vacuum tube affect the acceleration of the cabin? Is there any functions or equations to ...
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Explanation that air drag is proportional to speed or square speed?

A falling object with no initial velocity with mass $m$ is influenced by a gravitational force $g$ and the drag (air resistance) which is proportional to the object's speed. By Newton´s laws this can ...
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Why can you in physics exercises neglect the effect of air drag in case of basketball but not in the case of ping pong ball?

This is not a homework question or anything. I have finished schools and I always wondered why in physics exercises you can neglect the effect of air drag for example in case of basketball and I haven'...
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Finding the Initial Launch Velocity of a Ball Whose Launch Angle is Known and Trajectory Contains a Given Point (Accounting for Air Resistance)

I am working on a project that involves launching a ball through a basket (similar to basketball, but on a smaller scale for now). I haven't started building the project yet as I wanted to work out ...
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Object moving against drag: is location equal to $ln(time + c)$? [closed]

I'm creating an asteroids game. For player movement, I want the spaceship to be slowed down as if by a drag force, see e.g. https://en.wikipedia.org/wiki/Drag_(physics), and only the drag force. The ...
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Free Fall with Drag and Varying Air Density

I am trying to plot a graph in Excel describing a free fall of an iron sphere dropped from an altitude of 12 km, while taking into account the different levels of air density affecting the drag. The ...
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Power required to reach X velocity in X time with drag

I wrote a program that adds force to a car like so: Engine Force = Power / Velocity​ Drag Force = -Velocity²​ Net Force = Engine Force - Drag Force = Power / Velocity - Velocity²​ I'd like to ...
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How significant is the material in drag force calculations?

I went to Wolfram's "Drag Force Calculator" and received 4900 newtons for a cone that has a radius of 3 meters and a height of 3 meters, moving through air at a standard pressure, 15 celsius, at a ...
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What is meant with overdamped motion?

I'm learning about Brownian motion. I use the approximation of overdamped motion. I read that the average acceleration is $0$ then, but I don't really understand the concept. So, what does overdamped ...
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Sign problem in projectile with drag

So recently, I've been playing around with the variables in projectile motion with drag to see how the trajectory changes. I had my ODE and solved it using separation of variables but the equation ...
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2answers
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Optimize crossbow [closed]

I'm currently building a crossbow and was wondering how I might improve the performance of it? I was suggested to fine-tune the rubber band more and maybe change the projectile maybe to a zinc alloy ...
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1answer
132 views

Damped Oscillation and Period

In my school experiment, I wanted to measure the gravitational constant ($9.81 \ m/s^2$) by using a pendulum. If we take into account the damped oscillation (i.e. friction forces), does that affect ...
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1answer
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Velocity of object on extremely low air density?

If we derive velocity in air when setting air resistance to $kv$, we'll get $$v= \frac{mg}{k}\left(1-e^{\frac{kt}{m}}\right) $$ and if air density goes to $0$, $k$ will also goes to $0$. When $t=T$ (...
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What causes a soccer ball to follow a curved path?

Soccer players kick the ball in a linear kick, though you find it to turn sideways, not even in one direction. Just mid air it changes that curve's direction, i.e., it swings, as footballers say. Is ...
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Does the shape of the pipe (the length not the cross section area) affect resistive force?

Does the shape of the pipe (the length not the cross section area) affect resistive force acting on water? Does keeping the pipe straight or keeping it in curves folded over each other effect the ...
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Stop a car without static friction

If we want to stop a car really fast, we must put on the brakes in a way as to maximize static friction. The brakes create dynamic friction between the axle and the wheel, which in turn creates a ...
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Which formula is correct to find the terminal velocity of a sphere falling through a liquid?

Consider a sphere of radius $R$ & density $\rho_s$, falling through a liquid having density $\rho_l$, attains a constant terminal velocity $V_t$ then in this case the net force acting on the ...

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