Math Credit Challenge - Page 3

MrRubix · 11-9-2007, 11:22 PM

By the time you are at the halfway point having gone 20 mph, there is no speed you could go that would make the average speed 40 mph -- you'd have to somehow be at the destination the instant you hit the halfway mark given those assumptions.

You aren't given a distance, but that means we can assume one. Say it's 80 miles to the house. At the halfway mark you are said to be going 20 mph, which means it took you 2 hours to make it halfway (40 miles). For it to be an average speed of 40 mph at this point you'd have to cover the rest of the distance instantaneously, which would be the same as covering 80 miles in 2 hours, or 40 miles per hour in terms of average speed. As you can see, anything slower than instant travel will make the denominator larger, meaning a lesser average speed if you can't make the trip instantly.

**Reach** · 11-9-2007, 11:32 PM

Quote:

Originally Posted by Simonsmp

why isnt it 60 mph?

also, p=np
n=1

post of the thread

And 60 mph is the trap answer that 99% of people will give. Try comparing the time it would take to travel the whole distance with an average velocity of 40 with the time it takes to go halfway (v=distance/time). You'll run into a little problem, which I managed to solve.

I think the driver is Jean Luke Picard rollin down the street in the Enterprise.

MrRubix · 11-9-2007, 11:36 PM

Hehe n=1

Reach: Are we to assume that when Keeley is climbing the rope he is not applying any extra forces due to his pulling of body weight? ie. can we assume he is merely a weight moving up the string and doing nothing more than changing his relative displacement?

Hmmm, man it's been too long since I've done physics rofl. Always hated pulleys. I *think* I know the answer but I am not certain.

cvcbsaboy · 11-9-2007, 11:48 PM

**Reach** · 11-10-2007, 09:34 AM

Quote:

Originally Posted by MrRubix

I love these kind of physics problems.

Quote:

Originally Posted by MrRubix

Always hated pulleys.

>__>

MrRubix · 11-10-2007, 10:33 AM

These kind of physics problems = crazy physics problems
I still hate pulleys

**pokelda** · 11-10-2007, 11:45 AM

http://en.wikipedia.org/wiki/Millennium_Prize_Problems earn some cash or give me credits

**Reach** · 11-10-2007, 01:02 PM

I think the new rule should be you have to know the solution to your problem 8)

mike2727 · 11-10-2007, 02:14 PM

Quote:

Originally Posted by albaneenesk8r

mr rubix + FFR = ______

Soulmates. Credits pl0x.

**Nyokou** · 11-10-2007, 03:27 PM

I laughed really hard at

p=np
n=1

**pokelda** · 11-10-2007, 05:54 PM

Quote:

Originally Posted by Reach

I think the new rule should be you have to know the solution to your problem 8)

no screw you such rules are for wimps

TO_Leader · 11-11-2007, 04:48 PM

is he even going to ANSWER any of theese?

11-9-2007, 11:22 PM	#41
MrRubix FFR Player Join Date: Dec 1969 Location: New York City, New York Posts: 8,340	Re: Math Credit Challenge By the time you are at the halfway point having gone 20 mph, there is no speed you could go that would make the average speed 40 mph -- you'd have to somehow be at the destination the instant you hit the halfway mark given those assumptions. You aren't given a distance, but that means we can assume one. Say it's 80 miles to the house. At the halfway mark you are said to be going 20 mph, which means it took you 2 hours to make it halfway (40 miles). For it to be an average speed of 40 mph at this point you'd have to cover the rest of the distance instantaneously, which would be the same as covering 80 miles in 2 hours, or 40 miles per hour in terms of average speed. As you can see, anything slower than instant travel will make the denominator larger, meaning a lesser average speed if you can't make the trip instantly. Last edited by MrRubix; 11-9-2007 at 11:33 PM..

11-9-2007, 11:36 PM	#43
MrRubix FFR Player Join Date: Dec 1969 Location: New York City, New York Posts: 8,340	Re: Math Credit Challenge Hehe n=1 Reach: Are we to assume that when Keeley is climbing the rope he is not applying any extra forces due to his pulling of body weight? ie. can we assume he is merely a weight moving up the string and doing nothing more than changing his relative displacement? Hmmm, man it's been too long since I've done physics rofl. Always hated pulleys. I think I know the answer but I am not certain. Last edited by MrRubix; 11-9-2007 at 11:47 PM..

11-9-2007, 11:48 PM	#44
cvcbsaboy FFR Player Join Date: Feb 2005 Posts: 76	Re: Math Credit Challenge sec __________________

11-10-2007, 10:33 AM	#46
MrRubix FFR Player Join Date: Dec 1969 Location: New York City, New York Posts: 8,340	Re: Math Credit Challenge These kind of physics problems = crazy physics problems I still hate pulleys

11-10-2007, 11:45 AM	#47
pokelda ⁽ ´ཀ`⁾ Join Date: Jun 2006 Location: It is a mystery. Posts: 3,876	Re: Math Credit Challenge http://en.wikipedia.org/wiki/Millennium_Prize_Problems earn some cash or give me credits __________________

11-10-2007, 01:02 PM	#48
Reach FFR Simfile Author Join Date: Jun 2003 Location: Canada Age: 39 Posts: 7,471	Re: Math Credit Challenge I think the new rule should be you have to know the solution to your problem 8) __________________

11-10-2007, 03:27 PM	#50
Nyokou （￣ー￣） Join Date: Apr 2005 Location: United States Age: 34 Posts: 4,246	Re: Math Credit Challenge I laughed really hard at p=np n=1 __________________ Twitter \| Instagram \| Snapchat: Nyokou

11-11-2007, 04:48 PM	#52
TO_Leader FFR Player Join Date: Aug 2007 Location: United States Posts: 19	Re: Math Credit Challenge is he even going to ANSWER any of theese?

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