Which represents a longitudinal wave?

the motion of a spring

the motion of a shaking rope

the motion of a tight rubber band

the motion of an ocean wave

In longitudinal waves, the vibration or oscillation is parallel to the propagation direction of the wave itself . These disturbances are due to the successive compressions of the medium, where the particles move back and forth in the same direction as the wave.

This means, the closer together the particles are, the greater the amplitude of the wave. This is because of the distance between particles of the medium that is being compresed by the perturbation.

In this sense, the best example is the motion of a spring, since the air particles that are around the spring coil will oscillate in the same direction in which the waves propagate.

a skateboard rolling across the street - apex