200 Hz = 200 cycles per sec
<span>1 cycle, the period = 1/200 = 0.005 seconds, or 5 milli seconds.</span>
That's false. Mechanical waves (like sound and ocean waves) do
need a medium to travel in, but electromagnetic waves (like radio
and light) don't.
b. describes it best because a form of molten cools down and makes igneous rock. Good luck! Please mark me brainliest!
The answer is B. darker; cooler
the dark spots give off less energy then the rest of the sun.
Hope this helps
