Question

A 75 kg man is able to climb up 15 m in a 20 m ladder before it slips. What must be the coefficient of friction if the ladder is arranged so that its base makes at an angle of 50⁰ with the ground? Assume the ladder to be uniform and weighing 100 kg.

Answer 1

$\Sigma F=0,\implies N_A=75,$

$\Sigma M=0,\implies F_A=105,$

$\mu=\frac{N_A}{F_A}=0.71.$