A Ladder of length L and mass m leans against wall at angle theta from the vertical. The wall is smooth so that only horizontal force N is exerted on the top of the ladder. A fireman of mass M climbs a distance d upward as measured along the ladder.

(a): Assuming the ladder stays in equilibrium, calculate H and V, the horizontal and vertical force components on the foot of the ladder as a function of M,d,m,and theta.
(b): if the maximum horizontal frictional force H is related to V through H=u*V, what is the minimum coefficient of friction u required to prevent the ladder from slipping?
(c): Is a heavy ladder more or less safe for a given angle and coefficient of friction?

1 answer

A Ladder of length L and mass m leans against wall at angle theta from the vertical. The wall is smooth so that only horizontal force N is exerted on the top of the ladder. A fireman of mass M climbs a distance d upward as measured along the ladder.
(a): Assuming the ladder stays in equilibrium, calculate H and V, the horizontal and vertical force components on the foot of the ladder as a function of M,d,m,and theta.
(b): if the maximum horizontal frictional force H is related to V through H=u*V, what is the minimum coefficient of friction u required to prevent the ladder from slipping?
(c): Is a heavy ladder more or less safe for a given angle and coefficient of friction?