Supermarket engineering
In the design of a supermarket, there are
to be several ramps connecting different parts of the store. Customers
will have to push grocery carts up the ramps, and it is obviously desired
that this not be too difficult. An engineer has done a survey and
found that almost no one complains if the force required is no more than
50 N. Will a slope theta=5o be too steep (assuming a 30-kg
grocery cart full of groceries, moving at a constant rate)? You may
assume that friction (wheels against ground, wheel on the axles, and so
on), can be accounted for by a coefficient mk
= 0.10.