Answer:
Both rod have the same tensile stress
Explanation:
Given information,
The weight first rod, 
= 1000 N
The length of first rod, 
= 2.0 m
The weight second rod, 
= 500 N
The length of second rod, 
= 1.0 m
The equation of tensile stress, σ = 
where
σ = tensile stress (N/
or Pa)
F = Force (N)
A = Area (N/ or Pa)
so
σ1 = 
, A = 2πl
= 
= 
N/
now calculate σ2
σ2 = 
= 
= N/
σ1/σ2 = /
σ1/σ2 = 1
σ1 = σ2
Hence, the tensile stress of first and second rod are the same.
The shaft is 78m approximately deep. The correct option is D which is 78 meters
<h3>
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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