# 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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### 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. ...
0answers
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### Emperically Determining Terminal Velocity of a Sphere Falling over Critical Mach Number

I originally thought that the terminal velocity of a smooth sphere in free fall through the atmosphere would be an easy question to answer. But for heavy spheres of small diameter, the terminal ...
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### Force of air lift

Say I want to find out how much wind force I would need to lift a tank 10 meters in the air, given I already know its dimensions. Is there a formula for that?
1answer
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### Opposite of air resistance - Calculating the force

For a project on school I am making a program that can visualize physics in a two dimension space. Not the relativistic and quantum physics, but just the standard high school stuff. One of the things ...
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### Air resistance from several angles

Could one by using only 3 coefficients of air resistance, one for each axis $x$, $y$ and $z$, model the resistance on an object from any angle? So for example if one has a square, could one summarise ...
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### Stokes' law for disks [duplicate]

Stokes' law of viscous friction is famously applicable to spheres in (slow) motion within a fluid. If the object has radius $r$ and speed $v$, and the fluid has dynamic viscosity $\eta$, the dampening ...
2answers
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### Why large excavated holes can create air currents?

My friend shared this post on my wall, but I got doubt: How can a hole like this create air currents which suck helicopterss also? I didn't really understand.
1answer
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### Acceleration-Velocity function to Velocity-time function with non-constant acceleration

I've faced this question when trying to solve a test problem I had. The test, of course, did not require those functions to be expressed, but I just had to know what's going on. We're given a body ...
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1answer
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### period of a pendulum immersed in water

Does the value of $g$ change inside a dense fluid? How would the time period of simple pendulum change when immersed in water?
4answers
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### Terminal velocity on the moon? Is it possible and how long would it take? [closed]

Is there a way to find this out? If so please tell me the formula or just tell me how much time would it take for a 100 lb human to reach terminal velocity
6answers
991 views

### Distance from a velocity time graph where acceleration is not constant [closed]

In the following question I calculated the distance with methords actually only applying to constant acceleration. I thought this applicable because the question was asking for an approximation. I ...
1answer
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### Air resistance for practical purposes?

Doing a physics experiment where we are required to calculate the acceleration from gravity, for a simple high school assignment. And as part of an extended discussion, I would like to take into ...
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### How can i calculate the speed of a fan in a commercial jet engine?

How can i calculate the speed of a fan in a commercial jet engine if i already know the ρ(Air density), Cp (Maximum output), A (Rotor swept area), V(wind speed) and Drag coefficient? and what other ...
2answers
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### Trajectory with air resistance angle to hit target

How do I calculate the angle required to hit a target, I found this at Wikipedia: http://en.wikipedia.org/wiki/Trajectory_of_a_projectile This works very well but my problem is, that in my case air ...
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### Distance to reach terminal velocity in a viscous liquid

I have a physics exercise tomorrow and it's about a ball falling through a viscous (olive oil, ricin oil) liquid in a tube. I know this is not needed there but I would like to ask how to compute the ...
2answers
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### Why do flat objects land softly?

I noticed that if you drop a flat surface, parallelly from a relatively low height, onto another, the impact is almost cushioned. What is happening here? Is this to do with the air, especially near ...
1answer
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### Free fall and terminal velocity

An object in free fall is defined as one that is moving solely under the influence of gravity. So if an object has reached terminal velocity(force of gravity is cancelled out by upwards force of ...
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### Is it more efficient to load or tow a vehicle?

If I had a truck (a U-haul or similar) and needed to move a four-wheeled car from one location to another, would it require less energy (fuel) to load the car into the truck or tow it behind? A ...
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### Heat shields and the atmosphere

Space capsules and the Shuttles were equipped with heat shields to protect the spacecraft and those on board from the tremendous heat generated from friction as they reentered earth's atmosphere at ...
1answer
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### Most aerodynamic shape

What are the theoretical condition for a shape to be more aerodynamic? How can you design an aerodynamic shape without any experiment,just with equations?
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### Why do rifles impart rotation to bullets?

I have read at this site and at google that rotation of the bullet corrects the deviation from the target. Does anyone know how this is achieved?
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### Ohm's law for stones

Suppose I drop stones from a height. Now, we define quantity analogous to electric current called mass current. Now, to get an analogue to Ohm's law, we need drift velocity for stones. For electrons, ...