Answer:

Explanation:
l = Length of ladder = 8.57 m
m = Mass of ladder = 21.4 kg
F = Force on ladder = 258 N
= Angular acceleration = 
g = Acceleration due to gravity = 
Net torque is given by

The net torque acting on the ladder is
.
-- Conserve. Don't use more than we need. There isn't any more of it.
-- Conserve. Don't pollute what we have. There isn't any more of it.
Of course, what we REALLY need to do is <u><em>convince</em></u> great numbers of people to go along with these suggestions. Otherwise it won't work.