The acceleration is zero at the end points of the motion of a pendulum. Waves transport matter. There must be a medium for a wave to travel through. Waves do not have energy. All waves travel the same way.
Frequency is connected to loudness for all amplitudes.
Big waves travel faster than small waves in the same medium. Different colors of light are different types of waves. Pitch is related to intensity. Light is a particle. Light is a mixture of particles and waves.