Your written homework will be graded entirely on the clarity and completeness of
your derivation. No credit will be awarded for a final answer without a derivation.
As usual, simplify your final answers as much as possible.
A giant Pez dispenser of mass m rests on a ladder of mass M and length L. The
ladder is propped at an angle to the horizontal. The coefficient of static friction
between the ground and the ladder is S and the wall against which the ladder is
resting is frictionless. The Pez is a distance d up from the bottom of the ladder.
A) Draw an extended free-body diagram, showing all the forces acting on the
ladder and where they are acting.
B) What is the maximum mass m of Pez for which the ladder will not slip?
C) At a certain angle your expression for m becomes infinite. What is that
angle?
D) At another angle your expression for m becomes less than zero (negative).
Over what range of angles is the value of m negative?
E) What is the physical significance of these peculiar values of m?
1 answer
1 answer