Recent content by LJW

I drive an XR6 (Australian car, Ford Falcon variant) which is a 4L straight six. Awesome motor for a naturally aspirated, 270hp and 400Nm, and still gets good fuel economy for a large sedan. You can get turbocharged variants (XR6T/F6)- the F6 makes more than 400 horsepower stock, and monstrous...

Probably a small amount of lift (upwards downforce) raising the car slightly. Air resistance is very high at those speeds and without being powered the car would very rapidly slow down, lose downforce and come back to Earth.

Indeed. Don't bother trying to stop a thermite reaction, just let it finish. Do it on something non flammable that won't melt (i.e. ceramics, though they can often break). Plenty of space with nothing flammable nearby is the way to go. I certainly wouldn't do it inside a lab. Look, if it's not...

I think you're probably outside the bounds of the rules at this point. Kids improvising pyrotechnics, explosives at home and hurting themselves is certainly one thing the rules are to avoid.

Borek is probably the guy to clarify with- might as well. It wouldn't surprise me in the least if this was a thermite related thread, but is that an issue? I suppose it's a grey area- the thermite reaction is a common demonstration, though the rules forbid discussion of pyrotechnic/explosives...

Are you going to attempt a thermite reaction? I think it's suitable for this forum as it's a common chemistry demonstration. I'd recommend just buying the iron oxide and especially the aluminium powder if you are.

In the same boat as Vadar. Finding an engineer to do modelling for free won't be an easy task.

Yes, you are. You're used to living with gravity- and a lot of it, constantly. They aren't just sitting out there- they are moving apart from a central point. But they are certainly not "falling" as you suggested.

Why should it "fall"? Where would it fall to? Things fall when you drop them due to gravity. These aren't small objects near the surface of the Earth, they're massive objects in space. Though, everything is moving outwards from a point of origin- as proven by red shift. Gravitational pull does...

Note that I said "very similar", not "the same" It's true that the bullet in the atmosphere will stay in the air for very slightly longer. For practical purposes, not significant.

Well the answer is that the "rest mass" of the photos is 0- so when moving at the speed of light (the only speed they will move at) their relativistic mass is very low (and not infinite). Gravity isn't the only concern with objects that have mass. Even in an environment with a vacuum and no...

Do you mean create lift? In reality, nope. Bullets will (well, any accurate ones) rotate very rapidly and be uniform about the rotational axis. Ergo, no lift produced. A bullet with an aerofoil cross section would be terribly hard to stabilize. You've asked two questions. Air friction would...

Hi, To reach 100lb of force from a 3" sch.40 cylinder you'll only need about 13.5 psi which I assure you is very safe, especially in pipe pressure rated for potable water (often upwards of 100 psi). You could go to a fluid filled setup if you still have the safety concerns but it will be much...

They prevent unscrewing in applications where the screw fixes a rotating object, and also help to differentiate gas from hydraulic/liquid/etc lines in cars, burners, etc.

Because it isn't, simple fact. With reasoning and proofs you could very quickly prove it wrong. Surface area, volume, etc. of circles can be evaluated with integrals. i.e. integrating the circumference with respect to r yields the area of a circle. Integrating the surface area of a sphere...