Given a pendulum of length
L
and a point mass
M
with input
u(t)
as the force applied tangential to the direction of the motion of the mass shown in Figure 1, Figure 1: A pendulum. a) 2 points. Write an exact input/output differential equation using
\theta (t)
as the output. Hint: Themoment of inertia here is
I=ML^(2)
. b) 2 points. Classify this system: i. Memoryless, lumped, or distributed. ii. Causal or noncausal. iii. Linear or nonlinear. c) 2 points. Write a linear approximation of the input/output differential equation from part a) assuming
\theta (t)
is small. d) 2 points. Find the impulse response and transfer function of the system in part c).