average speed math

[mostsmooth]

1 mile oval
you average 60mph for the first of 2 laps
how fast must you go for the second lap to average 120mph for the two laps combined?
i apologize if this is too easy

[edtost]

the first lap took you 1/60th of an hour

to average 120mph for 2 mi, it must take you 2/120ths of an hour = 1/60th of an hour

=> the second lap takes 0 time

=> the second lap is taken at infinite speed.

[brassnuts]

YOU HAVE GO INFINITY MILES PER HOUR!

[mostsmooth]

[ QUOTE ]
YOU HAVE GO INFINITY MILES PER HOUR!

[/ QUOTE ]
thats pretty fast!

[disjunction]

not enough to make my commute worthwhile

[Patrick del Poker Grande]

[ QUOTE ]
1 mile oval
you average 60mph for the first of 2 laps
how fast must you go for the second lap to average 120mph for the two laps combined?
i apologize if this is too easy

[/ QUOTE ]
Lame-o! Welcome to the first day of [insert freshman-level engineering class here].

[Spaded]

[ QUOTE ]
1 mile oval
you average 60mph for the first of 2 laps
how fast must you go for the second lap to average 120mph for the two laps combined?
i apologize if this is too easy

[/ QUOTE ]

It is 180 if you count each lap seperately and time-independently. (180+60)/2 = 120. But if you go average speed by time it is different, since you spent 1/60th of an hour clearing the first lap, and you would spend less time going round the second time. Zero seconds, actually, because you would be taking two one mile laps at 1/60th of an hour = 120 mph average speed.

[ QUOTE ]
Lame-o! Welcome to the first day of .

[/ QUOTE ]

So [i]that's how you get a high post count, by saying that every thread sux! I oughta try that! /images/graemlins/tongue.gif

[Patrick del Poker Grande]

[ QUOTE ]
[ QUOTE ]
Lame-o! Welcome to the first day of .

[/ QUOTE ]

So [i]that's how you get a high post count, by saying that every thread sux! I oughta try that! /images/graemlins/tongue.gif

[/ QUOTE ]
Yes. It's all about the post count.

[Spaded]

It should be all about the benjamins

[kyro]

<font color="white">infinite mph. </font>

[Frequitude]

[ QUOTE ]
the first lap took you 1/60th of an hour

to average 120mph for 2 mi, it must take you 2/120ths of an hour = 1/60th of an hour

[/ QUOTE ]


When are you guys south of the 49th finally going to smarten up and use the metric system?

[jason_t]

[ QUOTE ]
[ QUOTE ]
the first lap took you 1/60th of an hour

to average 120mph for 2 mi, it must take you 2/120ths of an hour = 1/60th of an hour

[/ QUOTE ]


When are you guys south of the 49th finally going to smarten up and use the metric system?

[/ QUOTE ]

This problem has nothing to do with the metric system.

[edtost]

[ QUOTE ]
[ QUOTE ]
the first lap took you 1/60th of an hour

to average 120mph for 2 mi, it must take you 2/120ths of an hour = 1/60th of an hour

[/ QUOTE ]

has matric time been invented and put to common use elsewhere without my knowledge?


When are you guys south of the 49th finally going to smarten up and use the metric system?

[/ QUOTE ]

[jakethebake]

Are you suggesting coconuts migrate?

[KidPokerX]

so, you would need to run the second lap at 180mph? or infinite?

[AleoMagus]

[ QUOTE ]
so, you would need to run the second lap at 180mph? or infinite?

[/ QUOTE ]

infinite

Regards
Brad S

299 792 458 m / s or the speed of light as time would stop for the second lap.

[Siegmund]

Doing it at the speed of light is sufficient to make YOU think you've done it. But the official timekeeper, watching from the starting line for whom time was not dilated, will argue with you and say you didn't quite do it.

[mostsmooth]

maybe im stupid, but wouldnt the correct answer be "its impossible" rather than "infinitely fast"?

[LargeCents]

[ QUOTE ]
maybe im stupid, but wouldnt the correct answer be "its impossible" rather than "infinitely fast"?

[/ QUOTE ]

Nothing is impossible. Haven't you ever watched Rocky 5?

[mostsmooth]

[ QUOTE ]
maybe im stupid, but wouldnt the correct answer be "its impossible" rather than "infinitely fast"?

[/ QUOTE ]
well?

[andyfox]

"Haven't you ever watched Rocky 5?"

I tried, but I found it impossible.

Even when running it infinitely fast.

[Josh W]

hypothetically, if you go the speed of light, time stands still. so by going around the track at the speed of light, it takes no time. as such, you've gone around the track twice in 1 minute, averaging 120 mph.

josh

[usmhot]

No.
Firstly, time flows normally for you regardless of what speed you're travelling at. Time in other frames of reference that are travelling at different speed relative to you appear to flow at a different rates.

If you travel at the speed of light (impossible, but never mind) relative to the track then it will take exactly 1/c seconds (for c - the speed of light measured in miles per second) to cover the distance and 1/c is a finite number.

Aside: other limitations also exist, such as the assumption that you can accelerate from 60 mph to c in no time is false.

[Nathan183]

[ QUOTE ]
maybe im stupid, but wouldnt the correct answer be "its impossible" rather than "infinitely fast"?

[/ QUOTE ]

It depends on who's giving you the answer. If you consult a mathematician, he will tell you you must drive infinitely fast.

If you ask an engineer, he will tell you that it is impossible.

Both answers are correct, one is theoretical, the other is practical.

[NutzyClutz]

It depends how the arcade owner set up the machine. If completing the lap 1 at 60 miles per hour gave you bonus time..

[robokop]

[ QUOTE ]
If you travel at the speed of light (impossible, but never mind) relative to the track then it will take exactly 1/c seconds (for c - the speed of light measured in miles per second) to cover the distance and 1/c is a finite number.

[/ QUOTE ]
Err, but wouldn't the length of the track contract for you once you go c, so that you travel the distance at faster than 1/c seconds?

[usmhot]

The length of the track would appear to contract, but then time in the same frame as the track would also appear to move more slowly.

Part of the confusion here is the fact that the frames of reference aren't properly established. In fact we've got three frames of reference - with three different clocks - the track, the motion of the first time around, and the theoretical motion of the second time around.

Anyway, the point is, time would have to be measured in only one of the frames of reference for the entire attempt - so assuming its measured by an observer standing beside the track then the second circuit of the track (assuming it was at the speed of light) would take 1/c seconds.

Anyway, we can only go so far with this question before it really begins to break down - for example, we're also ignoring the fundamental problems such as getting from a small velocity to the speed of light in zero seconds.

[Nytecaster]

&lt;&lt;1 mile oval
you average 60mph for the first of 2 laps
how fast must you go for the second lap to average 120mph for the two laps combined?
i apologize if this is too easy &gt;&gt;

180mph for the second lap. Simple algebra to find the answer.

60 + x = 120 * 2

[usmhot]

[usmhot]

Your use of algebra is way off.
The equation you need to use to express it algebraicly is
time = distance / speed
giving
1/60 + 1/x = 2/120
x/60 + 1 = 2x/120
2x + 120 = 2x
x + 60 = x

which is clearly impossible - i.e. using this basic algebra you show its not possible.

[mindflayer]

The length of the lap and time it takes to do it are not relavent.

[ QUOTE ]
Your use of algebra is way off.
The equation you need to use to express it algebraicly is
time = distance / speed
giving
1/60 + 1/x = 2/120
x/60 + 1 = 2x/120
2x + 120 = 2x
x + 60 = x

which is clearly impossible - i.e. using this basic algebra you show its not possible.


[/ QUOTE ]

this is so dumb..put in the units and you get
1= distance 1m and 60 is mph.. then you have
1m/60mph = 1/60h = time = 1 minute to do the first lap
2m/120mph = 1/60h = time

so you are showing in your equation
1 minute + 1/x = 1 minute. how dumb is this.

I have to say i am pretty sure that 95% of the posts here are being sarcastic, because the answer is so simple.


the correct algebraic eq is
(60mph + xmph)/2 = 120mph

[bobman0330]

come on mindflayer, you're really hurting freq's Canadian pride push...

[Patrick del Poker Grande]

[ QUOTE ]
The length of the lap and time it takes to do it are not relavent.

[ QUOTE ]
Your use of algebra is way off.
The equation you need to use to express it algebraicly is
time = distance / speed
giving
1/60 + 1/x = 2/120
x/60 + 1 = 2x/120
2x + 120 = 2x
x + 60 = x

which is clearly impossible - i.e. using this basic algebra you show its not possible.


[/ QUOTE ]

this is so dumb..put in the units and you get
1= distance 1m and 60 is mph.. then you have
1m/60mph = 1/60h = time = 1 minute to do the first lap
2m/120mph = 1/60h = time

so you are showing in your equation
1 minute + 1/x = 1 minute. how dumb is this.

I have to say i am pretty sure that 95% of the posts here are being sarcastic, because the answer is so simple.


the correct algebraic eq is
(60mph + xmph)/2 = 120mph

[/ QUOTE ]
You fail. Hard. You are from here on out only allowed to be a mathemetician and not ever ever ever an engineer.

[Spaded]

This thread is so annoying! I always see it on the first page of this forum, it's a festering wad that never dies!

[Patrick del Poker Grande]

[ QUOTE ]
This thread is so annoying! I always see it on the first page of this forum, it's a festering wad that never dies!

[/ QUOTE ]
Agreed. Let's all just end it here. Stop.