# 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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### 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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### 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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### Dominant component of drag in a streamlined body (sounding rocket) at 0.8 Mach

We are currently working on CFD solutions on ANSYS Fluent for the drag on our sounding rocket. We are modeling its drag profile through out its velocity range. We currently hit a top speed of approx ...
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### Torque due to air resistance on a frisbee

In my analytical mechanics course we worked out an example involving a disk (say, a frisbee) rotating after being thrown into the air. The disk experiences a torque proportional to its angular ...
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### Projectile, air resistance and wind

So for my school project I am working on a projectile simulator and air resistance. So I have looked at this. Equations for an object moving linearly but with air resistance taken into account? ...
632 views

### Explaining the shape of a raindrop and a drop of mercury

I saw on wikipedia that the shape of a raindrop is explained by using Laplace pressure. But why? Since the drop is in motion, we shouldn't be able to use an hydrostatic law, am I wrong? The ...
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### Finding Time & Required Angle for Projectile Motion with Quadratic Air Resistance

This is a physics/calculus/computer science problem, but I think I'll get better results in the Physics SE. I have a fun little project I've been working on (hobby, not homework/production), that ...
37 views

### 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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### 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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### 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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### 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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### 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 $t=T$ (...