Question

A uniform ladder of mass m and length l leans at an angle q against a frictionless wall. A person of mass M climbs 90% of the way to the top (at 0.9l). Find an expression for the minimum coefficient of static friction needed to keep the ladder from slipping.

Answer 1

as ladder is in equlibrium so -oogl mi mg Toro ON f O= mg lq leso + Mg xoogleso -N₂ Isino I luso [m/t oogm N2 = f Ni= (M+mig sino in horizontal alirection f = N₂ L lig Ni = As(matM) g coso [m/+o.gm Ms? sino [M+ m) N2 Ni Answer