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'More Bridge Building' printed from https://nrich.maths.org/
Newton, from Macquerie Fields primary
school thinks that the bridges of even length will be the most
stable and not feel any forces at the joints. Is he right? Can you
use vectors and mechanics to help?
Fygliwu presents a very intuitive
mechanical explanation:
A bridge of even length should be less stable due to the fact
that it has a central point which bears a load. On a bridge of
uneven length this load is shared between a set of three points,
the two in the middle on the bottom and the one in the middle on
the top. This therefore means that the load of an uneven bridge is
spread out and therefore dissapated whilst the load of an uneven
bridge in focused on a single joint.
Can anyone supply mathematical
justification?