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.
Questions tagged [drag]
1152 questions
2
votes
2 answers
Air drag on a vertically thrown object
Air drag on a vertically thrown object is given directly propotional to its the square of its instantaneous velocity. But shouldn't it be linearly associated as air drag depends on amount of air displaced which is directly propotional to velocity?
N.S.JOHN
- 342
2
votes
2 answers
Is there a difference between "No Air Resistance" and "Constant Air Resistance''?
Is there a difference between "No Air Resistance" and "Constant Air Resistance''?
Like for example if we have two identical objects with different masses and we drop them from the same height.
Will their motions be the same if there is no air…
Maher
- 131
1
vote
1 answer
Heuristic derivation of air resistance - why should the velocity of the air be equal to the velocity of the car?
David MacKay gives a heuristic derivation of air resistance of a driving car in his book Sustainable energy without the hot air.
He starts with a tube of air with the cross sectional area of the car $A_{\text{car}}$ and the length $d$ which is the…
Marc
- 1,045
- 1
- 8
- 18
1
vote
1 answer
Drag force and Stokes' force
The drag force equation is,
$$F=1/2pAV^2$$
which means that it's proportional to the square of velocity. For Stokes' law, the drag force equation is,
$$F=6\pi\mu RV$$
which is proportional to the velocity (not it's square). What is wrong?
ergon
- 725
0
votes
1 answer
Is the drag coefficient same for two object with same shape, same size (radius) and same outer material but different mass?
I am doing an experiment where I want to measure the effect of the change of mass of the object to the terminal velocity of the object when falling down a liquid.
I am using a ping pong ball and I will use syringe to add water to the ping pong ball…
James
- 165
0
votes
1 answer
Interpreting a Formula for calculating Drag Force
I'm trying to build a tennis ball machine and I'm using a couple resources to help me out. One of them has the following formula for calculating drag force which I am having trouble interpreting.
The main question I have is what the V with a bar…
0
votes
1 answer
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 question. Does spinning affect air resistance? If…
Timothy
- 1,648
0
votes
1 answer
Simple estimate so see if air drag matters
When I create a projectile motion problem for students (in a course where air drag is neglected) I usually solve the problem numerically including drag. Then I plot the trajectory and compare it with that one obtained by neglecting the air drag.…
Julia
- 1,692
0
votes
0 answers
How to calculate wind force (air resistance) on a rectangular object?
Let's say you're driving down the road at 70mph (112 kph). If you hold a sign out of your window that's 20x20 cm square, how much force will be applied to the sign by the relative wind?
CaptainCodeman
- 1,286
-1
votes
1 answer
what are the assumptions for the drag force equation to work?
We know that the force of drag $F_{d}=\frac{1}{2}\rho u^{2}C_{D}A$. I can't find a list of the assumptions for it to work. What are the assumptions for it to work?
ergon
- 725