I believe destructive interference.
EXPLANATION: when two waves meet and a crest of one wave is parallel to the crest of another destructive interference occurs. You subtract the amplitude of the two waves that meet and you’ll get the amplitude of the wave they’ll form. If it is the same amplitude the result will be zero.
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An applied force must be applied to move a load. This applied force must be large enough to overcome any opposing forces in order to move the load.
The phonograph was invented for people with hearing problems. Option D is correct.
<h3>
What is a Phonograph?</h3>
- It is a device that records sounds or music in the grooves of a plate and plays them.
- This was the first invention that can record and play music.
- It was invented by Thomas Alva Edison.
- This device helps people with hearing problems by allowing them to practice concentrating on a different sound.
Therefore, the phonograph was invented for people with hearing problems.
Learn more about Phonograph:
brainly.com/question/858851