Intuitively, how does friction affect motion? Does the $v$ term
accomplish this to some level?
How does the equation relate to $F=ma$?
As a rough sketch without any calculation, what would you expect
the trajectory over time of the exact, real pendulum motion be over
time? Compare this to a plot of the solution. What would be
realistic values of the parameters? Make some well-reasoned
estimations if you have no intuitive sense for the scale of the
parameters.