Answer:
2270 full wavelengths.
Explanation:
The wavelength 
of the sound wave (assuming sound speed of 
) is
.
Now, assuming the distance to the last row is 1947m, the number 
of wavelengths that fit into this distance are
which is 2270 full wavelengths.
Hence, there are 2270 full wavelengths between the stage and the last row of the crowd.
Explanation:
Lodestone am iron were the only known magnetic materials in Gilbert's day, and his task was to investigate magnetism. Gilbert was so sure that the earth was a giant lodestone and used the earth as a primary reference, defining the north(magnetic) pole of a needle, or a a nail floating on a piece of cork, to be that which turns towards the Earth's north geographic pole. he wanted to prove this with a model Terella, using short pieces of iron.
Answer:
5 seconds
Explanation:
sound travels 1 km in roughly 3 secs so 1 mile in roughly 5 secs.
