How long until the water reaches the top step on this 5th grade brain teaser?

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In summary, a boat is docked at a shore, with a ladder hung from the top. The water-level is rising, and it will take 16 minutes for the water to reach the top step.
  • #1
physicsuser
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A boat is docked at a shore. A ladder is hanged from top of the boat So that the last step is touching the water. The distance between steps is 20 cm and there are 4 steps in the ladder. A tide is raising the water-level 5 cm a min. How long will it take for the water to reach the top step.
 
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  • #2
Phew ! :confused: That's a real toughie ! Luckily, I'm not in the 5th grade. :wink: :biggrin:

Otherwise, I may have complained about insufficient information ! :rolleyes:
 
  • #3
16 minutes
 
  • #4
gabe said:
16 minutes

I guess you're not in the 5th grade either, eh ?
 
  • #5
I'd say a 5th grader was trying to get his homework question answered. Hmm, smart enough to trick you but not smart enough to do the problem.

Ohh, and it is only 12 minutes.
 
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  • #6
ExtravagantDreams said:
I'd say a 5th grader was trying to get his homework question answered. Hmm, smart enough to trick you but not smart enough to do the problem.

Ohh, and it is only 12 minutes.

That would be the correct wrong-answer !
 
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  • #7
how is the boat docked? if it is far up on shore, not floating, and the tide level won't affect its position then i'd agree with the 12 minutes. however, if the boat is docked such that it is floating, then the tide won't move relative to the ladder.
 
  • #8
its a differential equation!

i donno :D
 
  • #9
The answer seems obvious to me. No math needed. But then I live down the street from a Marina.

(am I missing something?)
 
  • #10
Gokul43201 said:
That would be the correct wrong-answer !

Man I hate those
 
  • #11
Math Is Hard said:
The answer seems obvious to me. No math needed. But then I live down the street from a Marina.

(am I missing something?)

(No, you're not.)
 
  • #12
it will never reach the top step as the boat also rises with the tide.
 
  • #13
vikasj007 said:
it will never reach the top step as the boat also rises with the tide.

indeed. :smile:
 
  • #14
notice these two geeks used relativity for a 5th grade problem :tongue:


i still think there's a differential equation..
 
  • #15
cronxeh said:
notice these two geeks used relativity for a 5th grade problem :tongue:


i still think there's a differential equation..

Yes there is :

dx/dt = 5 = dy/dt

x(t=0) = 0

y(t=0) = 60

find t when x=y.
 
  • #16
hahaha funny
the boat will just rise so the water never rises up the ladder all the way-- unless the boat sinks
 
  • #17
well i am in 5th grade so probably wrong, but wouldn't the ladder rise with the boat
just a guess:biggrin:
 
  • #18
Tom McCurdy said:
hahaha funny
the boat will just rise so the water never rises up the ladder all the way-- unless the boat sinks

:rofl: :rofl: :rofl:
 

1. How long will it take for the water to reach the top step on this brain teaser?

The exact time it takes for the water to reach the top step will depend on a variety of factors such as the rate of water flow, the width and depth of the steps, and the type of material the steps are made of. It would require further analysis and experimentation to determine an accurate estimate.

2. Can you provide a specific time frame for when the water will reach the top step?

Unfortunately, without knowing the specific details of the brain teaser, it is not possible to provide a specific time frame. As mentioned before, various factors can affect the time it takes for the water to reach the top step.

3. Is there a mathematical equation or formula that can be used to calculate the time it takes for the water to reach the top step?

There may be certain equations or formulas that can be used to estimate the time it takes for water to reach a certain height. However, without knowing the exact details of the brain teaser, it is difficult to determine which equation or formula would be most appropriate.

4. Can you give an example of a similar brain teaser or experiment that can help us understand how long it will take for the water to reach the top step?

One possible example could be filling a bucket with water and measuring the time it takes for the water to reach a certain level. This could provide some insights into the flow rate of the water and how long it takes to reach a specific height. However, keep in mind that the brain teaser may have different variables and may not be directly comparable.

5. Are there any other factors that could affect the time it takes for the water to reach the top step?

Aside from the factors mentioned earlier, there could also be external factors such as temperature, humidity, and air pressure that could potentially affect the speed of the water flow. These may need to be taken into consideration when trying to estimate the time it takes for the water to reach the top step.

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