The main purpose of this talk is to introduce some new results on multiple rotational solutions for the planar forced $N$-pendulum. By using the Ljusternik-Schnirelman theory, we will show an abstract critical point result. Making special arrangements for masses and length instead of the nondegenerate assumption,we will show that for any given rotational vector $v$ with zero components and period $T\in[T_1,T_2]$, there exist at least $(N-N_0+1)2^{N_0}$ rotational solutions, where $N_0$ denotes the number of zero components of $v$.