Endercreeper01

We are arguing if pi or tau is the better circle constant

how would sinx=tanx=x with small angles? tanx=sinx/cosx

And also check out this link: www.tauday.org

But the size of the object changes relative to different observers

How is it insufficient?

So what do you think?

Re=Dvρ/μ according to my theory then they must have different reynolds numbers and also what would θ be for a half-sphere? I think it is 45. Is that correct? According to my theory, a half sphere and sphere have the same Cd. And also i found this link: https://www.google.com/url?sa=t&source=web&cd=2&ved=0CBIQFjAB&url=http%3A%2F%2Fwww.chem.mtu.edu%2F~fmorriso%2FDataCorrelationForSphereDrag2013.pdf&ei=V0QtUuChBNb94APqo4HICQ&usg=AFQjCNFux5E9ERsURhBQxTL8Zq5U-KqChw&sig2=Abqy5fRUhntiDepifZMMjQ it talks about Cd based on Re up to Re=107 so If i divide that by the cosine of 45, which is 21/2/2 then i get how to calculate the coefficient of drag for a plate up to Re=107. So the equation becomes 48/2^1/2 Re + 5.2Re/5)/21/2(1+(Re/5)1.52 + .822(Re/263000)-7.94/21/2(1+(Re/263000)8)+ 2Re0.8/463000*21/2

I know that, but according to my theory, they do. How can you be sure they don't? Its likely that they all have different Re

Yes, but then the object shrinks relative to an outside observer by a factor of gamma and so less light relative to them

The shapes all have roughly the same Reynolds numbers. The sphere and half sphere both have the same average angle and roughly the same Reynolds number, and so coefficients that are very similar. The same goes for the streamlined half- and full bodies. I don't know about the long and short cylinder because they must have very different Re, and I don't know the angle for the cone.

I cant just make the answers what I want, I have to use theory. It is 2 dimensional, and the closer that angle is to 90 degrees, then the less drag coefficient there is. It then must be dcosθ and d is the drag coefficient it would have at 0 degrees.

That imaginary plate is the basis for my theory

First, by x axis i meant axis perpendicular to direction of motion, and second, im talking about a 2 dimensional plate, not a 3 dimensional one It it about a 30% difference in the cosine of 0 and 45 degrees, so it is correct. And according to my theory, they would have Reynolds numbers that are roughly equal

Its not relative to the x axis, its relative to the surface perpendicular to the direction of motion. Just think about it. When that angle is 90 degrees, it is in 2 dimensions, and no part of it is interacting with the air at 90 degrees, so therefore, the coefficient is zero, and the total drag is zero.

No, because in the second case, then you would add that extra force to get the total air resistance when you want air resistance. Im talking about the coefficient of drag.

Fine, Ill pick Re=103. Now show me what it would be for a plate with that Reynolds number.

I can't find any graphs for a plate

According to the graph, it does both. And also, what do you think of my theory J.C.Maxwell?

Yes, but they don't agree on how much the light is blocked.

Average? it doesn't say the Reynolds number each shape had when being tested.

I agree with md - you are using bad reasoning to try and end critical thought:

I dont care what symbol we use, but for argument 2, then radius is better then diameter because a circle is defined by its radius.

How is that picture correct if the drag coefficient depends on Reynolds number?

What do you think I am missing? Re is covered in the part about the coefficient of drag for a 2d plate

Electromagnetism is mediated by photons, and in general relativity, gravity moves through curved space