The shaft is 78m approximately deep. The correct option is D which is 78 meters
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What are Sound Waves ?</h3>
Sound waves are longitudinal. That is, the direction of the waves is parallel to the direction of its propagation of particles.
Given that a boy finds an abandoned mine shaft in the woods, and wants to know how deep the hole is. He drops in a stone, and counts 4 seconds before he hears the "plunk" of the stone hitting the bottom of the shaft.
- The speed of the sound V = 330m/s
- The time it takes the sound to reach the top = t
Speed V = distance / time
330 = h/t
Make t the subject of formula
t = h/330
As the stone is dropped, initial velocity = 0, Using the formula
h = 1/2gT²
But T = 4 - t
T = 4 approximately
Substitute all the parameters
h = 1/2 × 9.8 × (4)²
h = 4.9 × (16)
h = 78.4m
Therefore, the shaft is 78m approximately deep. The correct option is D which is 78 meters
Learn more about sound wave here: brainly.com/question/16093793
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Answer:
the magnitude of the work done by the two blocks is the same.
Explanation:
The work done by block a on block b is given by:

where Fa is the force exerted by block a on block b, and d is the distance they cover.
The work done by block b on block a is given by:

where Fb is the force exerted by block b on block a, and d is still the distance they cover.
For Newton's third law, the force exerted by block a on block b is equal to the force exerted by block b on block a, therefore

and so

Answer:
or pure hydrogen
Explanation:
hope this helps you because this is the answer i have for you
Answer:
telescope
Explanation:
| AMNH. Before telescopes were invented, people gazed at the night sky with amazement and dreamed of a closer look. The invention of the telescope in 1608 gave humans their chance to explore the vastness of the Universe.