fast bloke

so how do you define suck then Bubba?

p.s. - Wife has gone to PTA meeting, crate of beer is chilling, this could go on for some time

fast bloke

"suction - the act of exerting a force on a gaseous body that draws it in by means of reduced air pressure"

Sounds to me that this is exactly what is happening

Tart Man

Thank god it didn't ask to explain inlet port scavenging on a 2 stroke

Bubba po

That question is so leading, and has so many wonderful but totally infractable answers, I'm going to exercise my right to silence.

Fuzz

****..

No7, No 37 and 48 wrong

Question 48 is well stupid, if the piuston didn't fecking move down the air wouldn't enter. ahh well, not bad and bloody good job I got a good score.

94%

J4CKO

iTrader: (1)

82%, would have got more if I could be arsed to read it properly, still I passed.

Simon C

74% and apparently I got the N/A question wrong. mmmmmmm.

RB5_245

90%, kicked myself at the first pullies question, messed up with the n/a engine too. I put it down to semantics though, the act of removing pressure from one area in order to draw in a fluid must be the definition of suction, despite the fact that is is actually the positive pressure outside that are that pushes the air in.

Also the definitions of reduction, reverse, overdrive and direct got me

All the answers they have are correct though.

mart360

lol i failed, maths / weights/pulleys stuff

Q48, wtf i was always taught suck squeeze bang blow

and one of the lights one was dubious, Q26. still trying to work out how a spur will turn off one bulb?

Mart

Fuzz

voltage takes the eaiest pass to earth, which isn't through the filament....

Jay m A

iTrader: (2)

Path of least resistance. i.e. sod the bulb, I'm off down the wire

Trust me. I'm a 90+ guy

Fuzz

Too slow... like the bulb

Jay m A

iTrader: (2)

Bet I finished quicker than you did

Fuzz

Ootheca

Thickies.

98% here.

It is the fan question which I take issue with as it isn't clear whether they mean "rotating the same direction" from the perspective of both sets of blades travelling in the same direction away from the view depicted or whether you are considering a strict clockwise/counter-clockwise interpretation viewing from the front of each fan.

RE: the suck/push argument, it's similar to the centripetal/centrifugal argument of a reactive force being the consequence of another in so far as that it is the atmospheric pressure actually doing the work of moving the air in and not the air sticking to the piston and being pulled in.

p.s. I don't like "path of least resistance', it sounds a bit noddy - assuming that the wire has negligible resistance compared to the bulb it is more technically correct to say that the potential across the bulb will be reduced to zero and therefore no current will pass through it.

dpb

It said the fans were identical,i thought ..!

Jay m A

iTrader: (2)

Look, if you're going to get picky - when you assume that the wire has negligible resistance, you should say negligible current will pass through the bulb, fan boy

Ootheca

Indeed, but that isn't the point I am making. The correct answer to that question was that both fans would turn in the same direction which it might look like from side on, however convention dictates that the direction of a fan or a prop should be described whilst looking along the axis of the shaft and from a consistent perspective e.g. from the front. Looking face on at each of the fans in turn one fan would be turning clockwise and the other would be turning counter-clockwise.

Fuzz

It's not about convention though, they gave you the picture to describe as is..

Ootheca

That's it, you're getting the hang of it.

It's the 'least resistance' part to which I take particular exception, because it implies that if the wire had slightly less resistance than the bulb that the current would still all "choose the path of least resistance" whereas we know that only some of the current would "choose" (urrgh) that path in a proportion inverse to the respective resistances.

fast bloke

That (fan one) was the other one I got wrong for similar reasoning. You would assume that to work out the direction a fan is turning you would look at it face on.

More importantly - Did you know that there is a little red x below your name and if you think it is appropriate to call people 'thickies' someone will press it and you will disappear. (OK - I am kidding, but there are a few sensitive (and thick) souls on here who might actually miss your smiley)

Anyway - Can you explain the 250kg masses with pulleys in terms of potential and kinetic energy and moments of inertia, cos I am 100% certain that it would sit tight until it go a push

jods

72% - That's an A******************** at A level now isn't it ?

jods

Path of least resistance - Nature Abhors a Vacuum

Still fooking failed

dpb

So your saying teh bulb will be slightly lit - exactly as i thought



i want my money back

Ootheca

Yes, it is about convention actually. In the absence of any other instructions convention is the only rule that one can use to describe the situation given.

Their answer is that both fans turn in the same direction. Strictly speaking they don't.

If you placed a merlin powered spitfire face on to a griffon powered one the props would be spinning in a manner the same as the above fan question... however convention dictates that the griffon spins anti-clockwise (from the pilot's perspective) and the merlin spins clockwise. No one would dream of ever saying that both props were turning in the same direction.

fast bloke

Try it and see - It won't be slightly lit even if you have infrared night vision owl goggles on. The wire in the spur will have no more resistance than the wire leading to the spur (unless it is a lower grade of wire, which isn't specified) so the spur will be able to cope with 100% of the load.

dpb

Theyd spin either way if you stepped on the clutch

dpb

they might even have feathering props , well never know

dpb

ohh ,all right then

Jay m A

iTrader: (2)

Exactly, path of least resistance you see