Let we have a ladder leaning on the wall. Initially we hold the ladder and as soon as we release it the ladder starts to slide.
My question: during the slide, are the friction forces at both ends constant or changing as the inclination angle changes (from $\theta_0$ to $0$)?
Addendum: Let assume $\theta$ in the angle between the ladder and the floor and the friction coefficient for both the wall and floor is $\mu$. Then we have fiction force between the ladder and the floor
$$F_f=-\mu mg \sin \theta,$$
and fiction force between the ladder and the wall
$$F_w=-\mu mg \cos \theta.$$
Since $\theta$ varies over time, both $F_f$ and $F_w$ will vary over time. And so the total force acting on the ladder, $F=mg-F_f-F_w$, also varies overtime. Am I correct?