A ladder whose length L is 12 m and whose mass m is 45
kg rests against a wall. Its upper end is a distance h of 9.0
m
above the ground, as in the figure on the right. The center
of mass of the ladder is one-third of the way up the ladder.
A fire fighter whose mass M is 72 kg climbs halfway up the
ladder. Assume that the wall, but not the ground, is
frictionless.
(a) Draw the normal reaction Nw exerted on the ladder by
the wall, the normal reaction Ng and the frictional force
fg exerted on ladder by the ground on the figure.
(b) Find the magnitudes of Nw, Ng and fg.