Ok here is a brain teaser for you

[Scottie]

At the local F1 race track, Eddie was testing the latest car. During the eight test laps, he managed to average:

- The first two laps at 100mph,

- The second two laps at 102mph,

- The third two laps at 140mph,

- The last two laps at 150mph.

What was his average speed for the entire 8 laps?

Clue: 123mph is not the answer!

[Big Col]

119mph aint it Fi?

[3GGG]

quote:Originally posted by Big Col
119mph aint it Fi?


Hmm, I made it 135.25 :I but I'm quite sure I'm wrong

[Scottie]

quote:Originally posted by Big Col
119mph aint it Fi?




dam how did you get it so quick:D:(

[Big Col]

quote:Originally posted by 3GGG
Hmm, I made it 135.25 :I but I'm quite sure I'm wrong


Did you? Hmmm. I was going to post how I done it to see if it was different from you but I don't want to ruin it for anyone else on here incase they're trying to get it. :D

[3GGG]

Don't tell us yet

[Scottie]

quote:Originally posted by Big Col
Did you? Hmmm. I was going to post how I done it to see if it was different from you but I don't want to ruin it for anyone else on here incase they're trying to get it. :D


I'll e-mail you how I dunit tomorrow;)

[Big Col]

quote:Originally posted by ScottieCoop
dam how did you get it so quick:D:(


YAY! :D

Like I say SC, I dunno if I should post how I done it incase others want to work it out. ;)

[Big Col]

You got mail SC. :D

[3GGG]

Well I can tell you how I worked out the wrong answer:

(100 + 102)/2 =101
(101+ 140)/2 = 120.5
(120.5+150)/2=135.25

Hmmm - must be missing something here - the 2 laps must have something to do with it, or is that a red herring?

[Big Col]

Remember your physics mate. You need 2 things to work out average speed. ;)

[3GGG]

quote:Originally posted by Big Col
Remember your physics mate. You need 2 things to work out average speed. ;)

Ah I get it - I know what I forgot -:I

[Scottie]

quote:Originally posted by Big Col
You got mail SC. :D


so do you:D

[3GGG]

quote:Originally posted by 3GGG


quote:Originally posted by Big Col
Remember your physics mate. You need 2 things to work out average speed. ;)

Ah I get it - I know what I forgot -:I


Nope still getting daft answers here despite knowing that average speed is distance/time and knowing that time is distance/average speed. :clown:

[3GGG]

s=ut+1/2at^2
v^2=u^2+2as
v=u+at
damn it - all these equations from applied maths and I can't work out average speed for a car doing 8 laps...

Now if it was a body on an inclined plane I could maybe get somewhere ;)

[3GGG]

Are we taking relativistic effects into consideration? :):clown:

I'm away for a wee dram;)

[3GGG]

Well I now get 119.02406 MPH but that was probably due to rounding errors in my calculator.

:blackeye::(

[3GGG]

As no-one else wants to be shamed by getting their logic/maths shown in public, I'll explain how I derived the above:

We need to calculate the average speed therefore we need the total distance and the total time.

total time =2/100 +2/102 +2/140 +2/150 = 0.0672268

average speed = total distance (2+2+2+2) / total time = 119.00016

Hmmm must be an easier way !
:dead:

Come on you young guys that have just passed your Highers :)

Edited to correct some rounding errors I had.

[Big Col]

That's the way I worked it out mate. Although I assumed a distance of 5 miles per lap. :)

[3GGG]

quote:Originally posted by Big Col
That's the way I worked it out mate. Although I assumed a distance of 5 miles per lap. :)


Got there in the end! - Thanks.

[Mon the fish]

His average speed is zilch, because what wasn't mentioned is that steady Eddie is on Michelins, so was called in at the end of the 8th lap and therefore didn't complete the race... :D:p

Where did I put that jacket?