Answer:
A crest is the highest point of a wave.
A trough is the lowest point of a wave.
Infrasound is sound below the limit that humans can hear, below 20 Hz.
Ultrasound is sound above the limit that humans can hear, above 20,000 Hz.
Answer:
5383 4983
i dont know
Step-by-step explanation:
Answer:
the answer is 19
Step-by-step explanation:
add a 1 to the 9 to make it a 10 add 10+10 to get 20 then subtract 1 to get 19. hope this helps :)
Answer:
Step-by-step explanation: