Answer:
a) x₀ = - 2 m , b) y = 4.47 m
Explanation:
A wave travels in the middle with constant speed, let's use the equation of uniform motion
v = d / t
t = d / v
The distance to the first listeners, see attached
d₁ = x₀-x
t = (x₀ +7) / v
The distance to the second listener
d₂ = x - x₀
t = (+ 3- x₀) / v
As the wave arrives at the same time, we can equal the two equations
(x₀ +7) / v = (3 -x₀) / v
x₀ + 7 = 3 - x₀
2 x₀ = 3 - 7
x₀ = -4/2
x₀ = - 2 m
b) The time it takes for the wave to reach the listeners of the x-axis, where the speed of sound is 340 m / s
t = 5/340
t = 0.0147 s
Let's look for the distance the wave travels for the listener axis and
v = d₃ / t
d₃ = v.t
d₃ = 340 * 0.0147
d₃ = 5 m
For the distance component we use the Pythagorean triangle
d₃² = x₀² + y²
y² = d₃² - x₀²
y = √ (d₃² -4)
y = √ (5² -4)
y = 4.47 m
We Know, K.E. = 1/2 × m × v²
From the expression, we can conclude that Kinetic energy is directly proportional to mass. So, as mass will increase, Kinetic energy will also increase.
In short, Your Correct answer would be Option B
Hope this helps!
The answer is 2.49 x 10^5 KJ. This was obtained (1) use the formula for specific heat to achieve Q or heat then (2) get the energy to melt the copper lastly (3) Subtract both work and the total energy required to completely melt the copper bar is achieved.
The third choice is correct
