My Math Forum  

Go Back   My Math Forum > High School Math Forum > Elementary Math

Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion

Reply
 
LinkBack Thread Tools Display Modes
September 10th, 2007, 04:57 PM   #1
 
Joined: Sep 2007

Posts: 2
Thanks: 0

Snail problem... find the equation algebrically..

A snail decides to climb a 12 meter well.

Every day, he climbs 3 meters in the daytime and slides 2 meters at night.

After how many days will he finally arrive at the other side of the well?
helpmeplz! is offline  
 
September 10th, 2007, 05:43 PM   #2
Global Moderator
 
CRGreathouse's Avatar
 
Joined: Nov 2006
From: UTC -5

Posts: 12,866
Thanks: 95

Re: Snail problem... find the equation algebrically..

Quote:
Originally Posted by helpmeplz!
After how many days will he finally arrive at the other side of the well?
That depends on whether I salt it or not.

What do you have so far?
CRGreathouse is offline  
September 11th, 2007, 01:36 PM   #3
Global Moderator
 
Joined: May 2007

Posts: 3,830
Thanks: 33

Re: Snail problem... find the equation algebrically..

Quote:
Originally Posted by helpmeplz!
A snail decides to climb a 12 meter well.

Every day, he climbs 3 meters in the daytime and slides 2 meters at night.

After how many days will he finally arrive at the other side of the well?
After 9 days the snail will be at the 9 meter mark. On the 10th day it will reach the top - hopefully it won't slide back any more.
mathman is offline  
September 11th, 2007, 04:10 PM   #4
 
Joined: Dec 2006

Posts: 1,111
Thanks: 0

Suppose that the rate at which the snail traveled decreased at a non-constant rate depending upon how long he had been traveling, and also depending upon the amount of salt being poured on him? :P
Infinity is offline  
September 11th, 2007, 04:42 PM   #5
 
Joined: Sep 2007

Posts: 2
Thanks: 0

Re: Snail problem... find the equation algebrically..

Quote:
Originally Posted by mathman
Quote:
Originally Posted by helpmeplz!
A snail decides to climb a 12 meter well.

Every day, he climbs 3 meters in the daytime and slides 2 meters at night.

After how many days will he finally arrive at the other side of the well?
After 9 days the snail will be at the 9 meter mark. On the 10th day it will reach the top - hopefully it won't slide back any more.
Yeah I get it but how do you do it algebrically? I need an equation.
helpmeplz! is offline  
September 11th, 2007, 05:05 PM   #6
Global Moderator
 
CRGreathouse's Avatar
 
Joined: Nov 2006
From: UTC -5

Posts: 12,866
Thanks: 95

Quote:
Originally Posted by Infinity
Suppose that the rate at which the snail traveled decreased at a non-constant rate depending upon how long he had been traveling, and also depending upon the amount of salt being poured on him? :P
Ooh, differential equations. I like.
CRGreathouse is offline  
September 12th, 2007, 12:49 PM   #7
Global Moderator
 
Joined: May 2007

Posts: 3,830
Thanks: 33

Re: Snail problem... find the equation algebrically..

[quote=helpmeplz!]
Quote:
Originally Posted by mathman
Quote:
Originally Posted by "helpmeplz!":3fjk7njk
A snail decides to climb a 12 meter well.

Every day, he climbs 3 meters in the daytime and slides 2 meters at night.

After how many days will he finally arrive at the other side of the well?
After 9 days the snail will be at the 9 meter mark. On the 10th day it will reach the top - hopefully it won't slide back any more.
Yeah I get it but how do you do it algebrically? I need an equation.[/quote:3fjk7njk]
H(n)=3+(n-1), where H is height after n days. Since you want H(n)=10, I think you can do the rest.
mathman is offline  
September 12th, 2007, 01:38 PM   #8
 
Joined: Aug 2007
From: turkey

Posts: 57
Thanks: 0

11 day
codename211 is offline  
September 12th, 2007, 04:00 PM   #9
Global Moderator
 
Joined: Dec 2006

Posts: 10,493
Thanks: 29

Quote:
Originally Posted by helpmeplz!
After how many days will he finally arrive at the other side of the well?
I don't understand. The snail is simply climbing upwards, so why does it ever reach the other side of the well? The standard (but tricky) problem of this type specifies a wall rather than a well, and you have to calculate how long it takes the snail to get to the point directly on the other side of the wall from the point where the snail started (so you have to include the time needed for the descent of the other side).
skipjack is offline  
October 2nd, 2007, 11:20 AM   #10
 
Joined: Sep 2007

Posts: 13
Thanks: 0

Quote:
Originally Posted by skipjack
Quote:
Originally Posted by helpmeplz!
After how many days will he finally arrive at the other side of the well?
I don't understand. The snail is simply climbing upwards, so why does it ever reach the other side of the well? The standard (but tricky) problem of this type specifies a wall rather than a well, and you have to calculate how long it takes the snail to get to the point directly on the other side of the wall from the point where the snail started (so you have to include the time needed for the descent of the other side).
lol so the distance from it started point to finish point is 24 meters =) how ever I believe the question maken by just for 12 meters.
Enochiche is offline  
October 2nd, 2007, 11:26 AM   #11
 
Joined: Sep 2007

Posts: 13
Thanks: 0

Re: Snail problem... find the equation algebrically..

[quote=mathman]
Quote:
Originally Posted by helpmeplz!
Quote:
Originally Posted by mathman
Quote:
Originally Posted by "helpmeplz!":1xq0tgc2
A snail decides to climb a 12 meter well.

Every day, he climbs 3 meters in the daytime and slides 2 meters at night.

After how many days will he finally arrive at the other side of the well?
After 9 days the snail will be at the 9 meter mark. On the 10th day it will reach the top - hopefully it won't slide back any more.
Yeah I get it but how do you do it algebrically? I need an equation.
H(n)=3+(n-1), where H is height after n days. Since you want H(n)=10, I think you can do the rest.[/quote:1xq0tgc2]

Re u sure this equation is giving the general solution? So if we think we got 12meters to take and if we got [one in a day] 3 steps up & 2 steps down( totally 1 step up) in 9 days we take 9 meters and 10th day first of all we ll take 3 steps up and we re 12 meters up already. Now c it at the solution;

u say H(n)=10 so then 3+(n-1)=10 and we've got n=8 here :/ I thnk thats not true.
Enochiche is offline  
October 2nd, 2007, 01:31 PM   #12
Global Moderator
 
Joined: Dec 2006

Posts: 10,493
Thanks: 29

I think "10" was just "12" mistyped.

Here's the trickier problem. Forget algebra; just try to solve it correctly.

A snail decides to climb a 20 foot wall (whose width may be ignored) and then climb down the other side of the wall.

He can climb up 3 feet in the daytime, but slides down 2 feet at night. Each day consists of 12 hours of daytime followed by 12 hours of night-time, so the snail is 1 foot up the wall at the end of the first 24-hour day.

After how long will he finally arrive at the foot of the other side of the wall?

(I've used feet to distinguish this problem from the previous one.)

Boring answers are wrong; you will know when you have the right answer!
skipjack is offline  
October 3rd, 2007, 10:46 AM   #13
 
Joined: Sep 2007

Posts: 13
Thanks: 0

Quote:
Originally Posted by skipjack
I think "10" was just "12" mistyped.

Here's the trickier problem. Forget algebra; just try to solve it correctly.

A snail decides to climb a 20 foot wall (whose width may be ignored) and then climb down the other side of the wall.

Every day, he climbs 3 feet in the daytime and slides 2 feet at night.

After how long will he finally arrive at the foot of the other side of the wall?

(I've used feet to distinguish this problem from the previous one.)

Boring answers are wrong; you will know when you have the right answer!

lol it can never arrive at the foot of the other side of the wall 'coz when it ll reach at the top of the wall it ll be 17th day and on the 18th day "climbin 3 feet in the daytime and slides 2 feet at the night" means ll be different(opposite)for it. thats why it can never reach to the foot point of the otherside of the wall.
Enochiche is offline  
October 3rd, 2007, 12:33 PM   #14
Global Moderator
 
Joined: Dec 2006

Posts: 10,493
Thanks: 29

Quote:
Originally Posted by Enochiche
. . . it. . .'ll be different(opposite)for it.
That doesn't make sense. The wall's thickness can be ignored, so the snail can certainly descend on the other side of the wall after reaching the top. However, I changed the wording slightly to remove any suggestion that the snail can't switch from ascending to descending. You should, of course, assume the snail doesn't make any unnecessary detours!
skipjack is offline  
Reply

  My Math Forum > High School Math Forum > Elementary Math

Tags
algebrically, equation, find, problem, snail


Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Find the model equation for this world problem? Ch13 Algebra 2 November 14th, 2013 03:58 AM
Cant Find XV Of this Equation! Andre Lopes Computer Science 2 September 1st, 2013 02:52 PM
Find the Equation drhingle Algebra 1 January 8th, 2012 07:25 PM
Find An Equation symmetry Algebra 4 November 28th, 2007 07:55 PM
Cant Find XV Of this Equation! Andre Lopes Algebra 0 January 1st, 1970 12:00 AM





Copyright © 2014 My Math Forum. All rights reserved.