## pde a chain oscillation

2. A flexible chain of length l is hanging from one end x = 0 but' oscillates
horizontally. Let the x axis point downward and the u axis point to the
right. Assume that the force of gravity at each point of the chain equals the weight of the part of the chain below the point and is directed tangentially along the chain. Assume that the oscillation are small. Find the PDE satisfied by the chain.