What are 2 uses for long radio waves;
and
what are 2 uses for short radio waves;

Long radio waves:
-- communicate with submarines
-- carry the time signals used to set your "atomic" clock

Short radio waves:  How short ? ?
-- 300 meters:  AM radio broadcast
-- 40 meters: International propaganda broadcast
-- 2.8 to 3.4 meters: FM radio broadcast
-- 2.5 meters: Aircraft communication to the ground
-- 1.7 meters: police, fire, ambulance, public safety radio
-- 0.3 to 1.5 meters: TV broadcast
-- 0.2 meter:  communication from GPS satellites
-- 0.15 meter: cellphones & smartphones
-- 0.12 meter:  cook leftover meatloaf in "microwave" oven