What is the sum of 1370 cm, 1575 mm, and 8.63 m in meters

-- waves on a Slinky

-- waves on a rope

-- waves on a guitar string

-- waves on a pond when you toss a stone in

-- waves on the ocean

-- waves on a cup of soup when you blow on it

-- seismic (earthquake) waves on the Earth's surface (if you're in a bad place)

All of those /\ so far are mechanical waves.

-- light waves, IF they happen to have the right wavelengths  (anywhere longer than infrared waves and shorter than ultraviolet waves)

That one /\ is an electromagnetic wave.