[k-man]

You are standing in front of a L-shaped trench. The trench is 5m wide, very deep and continues as far as you can see in both directions. All you found lying around are 2 boards that are strong enough to support your weight, but unfortunately they are both just a bit shorter than 5m. You have no rope, screws, nails or any other way to securely connect the two boards together. All you have are these 2 boards. How do you cross to the other side of the trench?

[curr3nt]

at the corner the length is sqrt(50) or 7.1

So set the first plank at the corner to form a 45-45-90 triangle then extend the 2nd plank from that plank to the other side of the trench

Planks would have to be longer than sqrt(50)*2/3 ~= 4.7

[Peekay]

Place the 2 boards at the corner of the trench as in attachment.

[Peekay]

You are standing in front of a L-shaped trench. The trench is 5m wide, very deep and continues as far as you can see in both directions. All you found lying around are 2 boards that are strong enough to support your weight, but unfortunately they are both just a bit shorter than 5m. You have no rope, screws, nails or any other way to securely connect the two boards together. All you have are these 2 boards. How do you cross to the other side of the trench?

How do you attach a drawing so that it is hidden (like a spoiler)? Being a Newbie, I didn't realize that the attachment would show.

[Guest]

I agree with the image attached by Peekay and the answer is CROSS THE PLANK to CROSS THE TRENCH :lol:

since you told that it is little less than 5 and since the distance between the edges will be 7.1 the distance to be covered will be about 2.5 which can be covered by the crossed plank

Edited April 6, 2011 by Shivam

[curr3nt]

How do you attach a drawing so that it is hidden (like a spoiler)? Being a Newbie, I didn't realize that the attachment would show.

The code for the attachment needs to be within the spoiler tags.

[k-man]

Curr3nt and Peekay got it!

[witzar]

It would be more interesting to ask what is the minimal length of the boards provided we have two boards of the same length.

[curr3nt]

It would be more interesting to ask what is the minimal length of the boards provided we have two boards of the same length.

I answered that in my post.

I calculated that the boards would have to be greater than sqrt(50) * 2/3

The first board would take you out to x/2. For the board to be stable the farthest end would need to be barely touching the walls. Safest answer also for not knowing the width of the boards.

the remaining distance would be x

so x/2 + x > sqrt(50) => 3x/2 > sqrt(50) => x > sqrt(50) * 2/3

It would need to be just longer to give enough board to balance on the 1st plank and the corner.

Then again putting weight on the 2nd board would possibly upset the balance of the 1st board. We would need to know weights involved to get a better answer.