A primary source is where the information comes directly from the original copy or someone who experienced it first hand, and where as a secondary source is someone or something that was not there when the event took place- hope this helps!!
Answer: The compression pulse which is produced when the hammer hits the metal bounces backwards and forwards within the metal. Most of the pulse (sound wave) is reflected within the metal rather than transmitted outside the metal into the air because the speed of sound in a metal is much bigger than the speed of sound in air.
Explanation: Brainelist Me
To express emotions that the simple words that were already created could not explain
The answer is D. Page 1478, second to last sentence to confirm it youself.
