Question 5

Posted in: Design

After the maths of last week's question, here is something to make your brain work in a slightly different way!

UPDATE: Its about real world design and the implications of inaccuracies in construction.

A person weighing 600N sits on a three-legged stool.  For what basic force should each leg be designed? There is no catch to this problem - the stool is to be symmetrical, the person sits in the center of the seat.  The answer is of course  200N

The same person now sits on a square  stool with four legs, one at each corner and again the stool and the loading are symmetrical. For what force should each leg of the stool be designed?

You can assume the floor is flat and rigid! Once you have decided how much load each leg should be designed for, please answer the question below.

Which type of stool uses the least  amount of material in the design of each leg?

Voting  is now closed!

Well done to the 62 people that entered the quiz. If you consider that the length of each leg maybe very slightly different, then the 3 legged stool is by far the best design requiring 50% of the material in the legs than the 4 legged stool.

If you didn’t get this answer please read through the SOLUTION.


Posted in: Design


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