Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula

I₀ = 10⁻¹² W/m²
now,



to hear the whisper sound = 80 dB



we know intensity of sound is inversely proportional to square of distances



r₂ = 0.2 m
meter, millimeters, kilometers. liters. kilograms. centimeters etc... look up the rest
While the answer is that it does, it transmits light VERY poorly. Most of the light bounces off it and the rest is refracted into the ocean. This is why you can't see much that is far away from you in the ocean unlike if you're just on land.
Answer:
it is sooo easy u need to use magnetic panels on the rail and put the magnet on the train it works under the principal of magnetic