When crest of one wave interferes with the trough of other wave, the amplitude of the resultant wave formed is less. Hence the type of interference is destructive interference.
The concept that we need here to give a proper solution is mutual inductance.
The mutual inductance is given by the expression

Where,
I = current
N = Number of turns
Flux through the solenoid.
Part A) Then we have in our values that,



Replacing in the equation,


Part B) Here is required the Flux, then using the same expression we have that

We conserve the same value for the Inductance but now we have a current of 2.6, then


Therefore the flux in Solenoid 1 is 
Wave speed = (wavelength) x (frequency)
= (1.5 m) x (500 / sec)
= 750 m/s .
Answer:
The energy dissipated as the puck slides over the rough patch is 1.355 J
Explanation:
Given;
mass of the hockey puck, m = 0.159 kg
initial speed of the puck, u = 4.75 m/s
final speed of the puck, v = 2.35 m/s
The energy dissipated as the puck slides over the rough patch is given by;
ΔE = ¹/₂m(v² - u²)
ΔE = ¹/₂ x 0.159 (2.35² - 4.75²)
ΔE = -1.355 J
the lost energy is 1.355 J
Therefore, the energy dissipated as the puck slides over the rough patch is 1.355 J