3.3.11. A pendulum of length $l$ is suspended near an inclined wall. The pendulum is displaced from the vertical by a small angle that is twice the angle of inclination of the wall from the vertical, and then released. Find the period of oscillations of the pendulum, assuming that the collisions with the wall are perfectly elastic.
For problem $3.3.11$
Solution
Answer
$$v = -A\omega \sin \omega t, \quad a = -A\omega^2 \cos \omega t, \quad F = -m\omega^2 x = -A m \omega^2 \cos \omega t, \quad k = m \omega^2.$$
