I'm not even sure what the diagram would look like for this:

A ladder 9m long is to be moved horizontally around a 90 degree corner from one corridor 2.5m wide into a second corridor. How narrow can the second corridor be and still permit the ladder to go around the corner? Neglect the width of the ladder.

Originally Posted by pereeia
I'm not even sure what the diagram would look like for this:

A ladder 9m long is to be moved horizontally around a 90 degree corner from one corridor 2.5m wide into a second corridor. How narrow can the second corridor be and still permit the ladder to go around the corner? Neglect the width of the ladder.

You can't neglect the width of the ladder!

It depends on if you hold the ladder so the rungs are horizontal or vertical.

It says you're carrying the ladder horizontally, so the ladder would be on its side if that makes sense.

Originally Posted by pereeia
I'm not even sure what the diagram would look like for this: A ladder 9m long is to be moved horizontally around a 90 degree corner from one corridor 2.5m wide into a second corridor. How narrow can the second corridor be and still permit the ladder to go around the corner? Neglect the width of the ladder. The answer is 3.92m.
Originally Posted by SGS
You can't neglect the width of the ladder!
It depends on if you hold the ladder so the rungs are horizontal or vertical.
Only the length matters.
Look at the diagram.

BTW. I once was at a University where the civil engineers of all people built a new building. Then they had custom made cabinets done. But the cabinets could not be moved in because they would not round the corners. Those of us who taught their students calculus had great fun when coming to this very question.

Originally Posted by Plato
Only the length matters.
Look at the diagram.

BTW. I once was at a University where the civil engineers of all people built a new building. Then they had custom made cabinets done. But the cabinets could not be moved in because they would not round the corners. Those of us who taught their students calculus had great fun when coming to this very question.
This is of course correct for this problem.

In real life you can also rotate the ladder parallel to the walls and gain a fair bit more leeway.

I know this from having done painting and having had to move ladders all over the place in narrow corridors.

Originally Posted by Plato
Only the length matters.
Look at the diagram.

BTW. I once was at a University where the civil engineers of all people built a new building. Then they had custom made cabinets done. But the cabinets could not be moved in because they would not round the corners. Those of us who taught their students calculus had great fun when coming to this very question.
Thanks man. I managed to solve the question thanks to your diagram.