Answer:
activation energy hope this is right
There are some methods that differentiate waves; one thing is by its medium.
Electromagnetic waves did not require a medium for transmission such as in a
vacuum while mechanical waves require a medium to travel such as air, water or
anything that can serve as a transmission aid.
The most common sample of EM waves in
telecommunication is radio,
light and infra-red signals. An example of a mechanical wave is a sound
wave, which requires air to travel. Oscillating molecules made the
sound waves.
Plant cells have plastids, cell wall, large and permanent vacuoles whereas animal cells don't
