Number six, me ! i looked in my text book but cant find anything

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!

What type of electromagnetic waves does the human eye see as the colors red blue or green a visible light waves b radio waves c infrared waves d microwaves

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?