Answer:
The tension is 75.22 Newtons
Explanation:
The velocity of a wave on a rope is:
(1)
With T the tension, L the length of the string and M its mass.
Another more general expression for the velocity of a wave is the product of the wavelength (λ) and the frequency (f) of the wave:
(2)
We can equate expression (1) and (2):
=
Solving for T
(3)
For this expression we already know M, f, and L. And indirectly we already know λ too. On a string fixed at its extremes we have standing waves ant the equation of the wavelength in function the number of the harmonic
is:

It's is important to note that in our case L the length of the string is different from l the distance between the pin and fret to produce a Concert A, so for the first harmonic:

We can now find T on (3) using all the values we have:


Answer:
Explanation:
Given
Total time=27 min 43.6 s=1663.6 s
total distance=10 km
Initial distance 
time taken=25 min =1500 s
initial speed 
after 8.13 km mark steve started to accelerate
speed after 60 s


distance traveled in 60 sec


time taken in last part of journey

distance traveled in this time


and total distance



I believe the answer is C
The loudness was increased by the amplifier which converted electrical energy into sound energy.