metre per second
velocity of sound (phase velocity), group velocity
(instantaneous) sound particle velocity
phase velocity of electromagnetic_x000D_ waves, phase speed of electromagnetic waves
velocity, phase velocity, group velocity
velocity (speed) on propagation of electromagnetic waves in vacuo
neutron speed
Space and Time
Acoustics
Light and Related Electromagnetic Radiations
Nuclear Reactions and Ionizing Radiations
Electricity and Magnetism