Questions For The Maths Gurus

[Guest INASNT]

I need a few calculations which i could do myself but i cbf getting out notes or books to work em out.

Questions :

If u were travelling at 130km/h for 800m how long (seconds) would it take to travel that distance?

How long would it take to come to a complete stop from 130km/h and how many meters to stop in a normal VT commodore V6?

How many seconds would a VT commodore exec take to accelerate to 130km/h and and how many meters would it take for it get to 130km/h?

[strutto]

If u were travelling at 130km/h for 800m how long (seconds) would it take to travel that distance?

22.153846153846153846153846153846 seconds...

[Guest INASNT]

and ur calculation for that is?

[BB GoDZilLa]

130kms / 60 minutes = 2.16

2.16kms travelled in 1 minute

800 / 2160 = 0.37

0.37 * 60 = 22.2

so to answer your question I think it takes 22.2 seconds

[strutto]

and ur calculation for that is?

Shit... You didnt say we had to show workings...

130 km/h = 130000m/3600sec

130000m / 800m = 162.5

3600 / 162.5 = 22.153846153846153846153846153846

:headspin:

[Guest INASNT]

yep those calculation seem right.

the important thing i need to know is how many meters it would take for a crapadore VT 6 to get to 130km/h and how many seconds, and how many meters and seconds to come to stop from that speed???

[Clint32]

yes you could work out the stopping distance/time but there are many things that are required, weight, brake size, caliper dimensions, brake pad material and others as well i think, not worth the effort really

same for the acceleration, many factors that affect the time and probably wouldnt be overly accurate

[Guest INASNT]

nromal vt crapadore, doesent have to be 100% correct

[Guest Munky]

22.153846...... seconds to go 800 metres

To do this just work out how many metres per second the car is travelling at (its speed / 3.6)

Then divide 800 by the figure you get from the above calculation.

Basically its just a case of manipulating the simple identity

Velocity = Distance / Time once you get the velocity in m/s

its pretty hard to do the acceleration question without some figures to go with it (ill look for some)

[Guest Munky]

How many seconds would a VT commodore exec take to accelerate to 130km/h and and how many meters would it take for it get to 130km/h?

Using the figures of a supercharged 5.7L V8 Commie VT (So it's inaccurate - I couldnt find figures for the one u specified)

Assuming it accelerates at constant acceleration, and using the figure of 5.89s 0-100kph

v = u + at

0 = 100 + 5.89a

therefore a = approx. 17 km/s

So now using v = u + at again

130 = 0 + 17t

therefore t = about 7.64 seconds

Now just doing a simple calculation of distance travelled = 1/2vt

The distance travelled is about 138 metres

I think that should be right but I havent done any mechanics/physics questions for about 7 months (since I finished hsc) It sounds right though (at least for a supercharged 5.7L v8)

I think you'll find that you can't do the stopping question without a figure on the deceleration figures of a commie.

[Guest INASNT]

I havent used these formulas dor 4 years since i finished uni

Thanks for the info.

If u go by 1/4 times for a exec commo dont they do 16 in the 1/4, but at what speed?

[LaL]

LOL DID YOU MAKE A BIT WITH ONE OF YOUR MATES ? let me geuss youse had a arguement about how fast etc and stuff his car goes ? LOL

[Guest INASNT]

LOL DID YOU MAKE A BIT WITH ONE OF YOUR MATES ? let me geuss youse had a arguement about how fast etc and stuff his car goes ? LOL

nope nothing to do with bets with mates.

more to do with court and proving facts regarding speeding

[Guest Munky]

If u go by 1/4 times for a exec commo dont they do 16 in the 1/4, but at what speed?

It's almost impossible to figure this out because once your doing 100km/h obviously your car won't accelerate at the same rate as it was for 0 - 100. So its speed might only increase by 40km/h in the last 10 seconds of the 16 secs (as opposed to the 100 km/h it increased in the first 5.98 seconds if ur using the supercharged specs)

That's why the original calculation probably isnt very accurate either, since I just took the average rate of acceleration and assumed it was constant for the entire 0 - 100 (then kept assuming it was constant till 130km/h) In reality it would take longer since the car won't increase in speed as quickly as it did off the mark (ie. the rate of acceleration will drop so that the rate of acceleration by 130km/h is no longer 17km/s^2)

[EnricoPalazzo]

using mechanics, u can get a more precise answer. I wont work it out thou, too hard..

[predator]

% chance that this crap isn't really going to help Inasnt in court - 99%

[Zahos]

how long is a piece of string????

i think there are too many things to take into consideration to calculate this...

Maybe call holden and ask them, as I am sure they would have these sorts of results when they do their testing.

[ferni]

borrow a VT and test it - best way

[2rismo]

Someone get clocked by a NON-RADAR-EQUIPPED police vehicle huh?

Sounds like you're trying to work out if they were following you for long enough to get an accurate guesstimation of your vehicles speed... That and they must have been going in the other direction when they saw you...

Am I close?

Good luck dude.

Adrian

[red900ss]

This defence has ben used previously in at least one case to the benefit of the defendant. If the calculation works out you will win. The difficulty is proving the data is correct.