This is my first puzzle not on pure mathematics. Currently
it is revision season and at school we are getting slightly tired of repetitive
past paper questions on mechanics. Therefore, we recently spent an afternoon
trying to come up with interesting mechanics questions. This puzzle I did enjoy
because some logical thinking is needed to solve it. Here is the puzzle.
Four rough blocks of mass 5kg are stacked on top of each other
on a rough horizontal surface. A 20N force parallel to the surface is applied to
the second block upwards and the whole system is in equilibrium. Calculate the
possible values for the coefficient of friction between the blocks. You may
assume toppling does not occur. I have provided a diagram of the situation
below to help.
