Speeding at Duxford

[simond001]

Can any of the "traffics" who are attending Duxford bring a speed camera along, be nice to see how fast we are going!!

[pbrettle]

Alternatively can someone with a brain for maths be there - the length of the runway will be known as will the timing. Therefore we can work out the time / distance travelled - i.e. speed....

But the conversion needed is beyond my simple brain

Cheers,

Paul

[JonRB]

Well the clue is in "miles per hour". That's distance / time. Take the distance in miles, divide by the time in hours and you get mph.

Phew! I knew my PhD in Maths would help eventually.

[davidy]

But thats average speed, not terminal velocity at a particular point, which the speed gun could give you (with an experienced operator) or you need two sets of timing beacons set a known short distance part (speed trap?) and then your Maths PhD is invaluable

davidy

[JonRB]

Not really. You just measure the time it takes to travel a known distance (eg. the distance between two points) and then perform the above calculation.

At the end of the day the Police VASCAR is just a glorified stopwatch that does this calculation and gives a speed.

(I acknowledge that VASCAR can do more than this, before I'm pounced on, but at its most basic level my comments are true)

[Bonce]

Why doesn't somebody dig up a camera from the A14 and take that along? As well as providing a nice record of actual speeds, you could sell the pictures to drivers 'caught' at 160mph on the runway.

[simond001]

Thats a no then

[bobthebench]

If you're really interested, you can hire speed guns from HSS hire shops, or the gadget shop sells them now, pricey at £300 though.

[xsaravtr]

Check out the HSS website www.hss.co.uk
£57 a day.

Go to Safe and Sure section and then Measuring and Maintenance then Speed Control...

[Paceracing]

You could calculate terminal velocity if you could calculate acceleration. I've forgotten the formula but vaguley remeber that '1/2AT squared' was part of it.
Can anyone remember the rest of it?

Jas.
P.S. I need to get out more!

[GregC]

You could always check the speedo for a free rough guide to top speed...?

[yum]

Higher tech options are accelerometer and gps, which will give exact acceleration speeds and velocity at any given time.

I won't be there, but I'm sure that some at duxford will have them.

[Fatboy]

quote:You could calculate terminal velocity if you could calculate acceleration. I've forgotten the formula but vaguley remeber that '1/2AT squared' was part of it.
Can anyone remember the rest of it?

Jas.
P.S. I need to get out more!

The formula is:
s=ut + (1/2)a(t*t) where t is time, s is distance, a is acceleration and u is initial speed.

[Marshy]

Oi, clear off you lot I tried very hard to forget all this formulaic tosh 13 years ago, and you're all throwing it back in my face.

The worst part of it is, just like cigarettes, you get one sniff of something and it all starts to come back. s=ut + 1/2a(t^2) is just the start of a slipperly slope...

Er.