The continent located 40n and 100w is North America
The work to stretch a spring from its rest position is
(1/2) (spring constant) (distance of the stretch)²
E = 1/2 k x² .
You said it takes 1700 joules to stretch the spring 3 meters from its rest position, so we can write
1700 joules = 1/2 k (3m)²
1 joule = 1 newton-meter
1700 N-m = 1/2 k (3m)²
Multiply each side by 2: 3400 N-m = k · 9m²
Divide each side by 9m² k = 3400 N-m / 9m²
= (377 and 7/9) newton per meter
The lower the frequency the lower the pitch sound.
Assume that the small-massed particle is 
and the heavier mass particle is 
.
Now, by momentum conservation and energy conservation:
Now, there are 2 solutions but, one of them is useless to this question's main point so I excluded that point. Ask me in the comments if you want the excluded solution too.
So now, we see that 
and 
. So therefore, the smaller mass recoils out.
Hope this helps you!
Bye!
You're answer is B. P waves are more dynamic and have a great autonomy to be able generate a earthquake.
