<span>James Clerk Maxwell is the answer</span>
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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Answer:
8 x 10⁻⁷ x I / r
Explanation:
Two parallel long wires are carrying current I . Let the direction be towards the right in the farthest and towards the left in the nearest. Magnetic field due to current I at a distance d is given by the expression
B = μ₀ 2 I / 4π d
I the present case distance d = r/2
Magnetic field due to one wire at point d = r/2 is
B₁ = μ₀ 2 I / (4π r / 2 )
= 10⁻⁷ x 4I / r
Magnetic field due to the other wire at point d = r/2 is
B₂ = μ₀ 2 I / (4π r / 2 )
= 10⁻⁷ x 4I / r
Direction of magnetic field due to both the wires at the mid point P will be same . It will be in downward direction in the given scenario
So total magnetic field
B = B₁ + B₂
= 2 x 10⁻⁷ x 4I / r
= 8 x 10⁻⁷ x I / r
A projectile has some form of thrust to propel it in the desired direction, while an object in free fall has no extra force guiding/propelling it