Math Credit Challenge

[MixMasterLar]

Re: Math Credit Challenge

if you can go metric = english then Im out 100 credz rofl....but I'll try

Ok, how much dirt (measured in km)is in a hole if the hole is:

13 feet deep
8 feet wide
9 feet long.

[Reach]

Re: Math Credit Challenge

if you can go metric = english then Im out 100 credz rofl....but I'll try

Ok, how much dirt (measured in km)is in a hole if the hole is:

13 feet deep
8 feet wide
9 feet long.

omg none...!

[Problems]

Re: Math Credit Challenge

This is really a very simple problem, but many people find it very counter-intuitive.

You are driving by car to a particular destination, and our only assumption is that you are free to drive at any speed you choose - no traffic jams or anything like that. For the first half of the journey (and by half we mean half the overall distance between the starting point and your finishing point) you drive at 20 miles per hour. You then realise that this is all taking much too long, and that you are going to be late. You therefore decide that you will increase your speed so that your overall average speed for the whole journey will be 40 miles per hour. How fast do you have to drive for the remaining part of your journey in order for your average speed for the whole journey to be 40 miles per hour?

Also, I know this is a pretty popular problem so don't google it. It'll spoil the fun. And this problem is on about an eigth grade level if you read it correctly. If you can't get this, which I very highly doubt, i'll give a hint.

[MrRubix]

Re: Math Credit Challenge

Problems: Impossible to do unless you somehow possess a teleporter.

Credits please

[MrRubix]

Re: Math Credit Challenge

Reach: There are tons of things going on assuming I am doing it right. I am just hoping I am not making an incorrect assumption somewhere.

[Reach]

Re: Math Credit Challenge

LOL.

v2= infinity (where acceleration is infinite, starting from exactly the halfway point).

>__>


edit: gl rubix

[MrRubix]

Re: Math Credit Challenge

rofl

[Problems]

Re: Math Credit Challenge

Haha, pretty much. That one was incredibly easy. I'll give you a harder one later. Credits sent.

[Tasselfoot]

Re: Math Credit Challenge

lucky for us, i have a teleporter!

edit: also will give the physics problem to my buddy, who is much better at solving those kinds of problems than i.

[Simonsmp]

Re: Math Credit Challenge

why isnt it 60 mph?

also, p=np
n=1

[MrRubix]

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.

[Reach]

Re: Math Credit Challenge

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]

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.

[cvcbsaboy]

Re: Math Credit Challenge

sec

[Reach]

Re: Math Credit Challenge

I love these kind of physics problems.

Always hated pulleys.

>__>