A. A clastic Sedimentary rock
To solve this problem it is necessary to apply the concepts related to frequency and vibration of strings. Mathematically the frequency can be expressed as

Then the relation between two different frequencies with same wavelength would be


The beat frequency heard when the two strings are sounded simultaneously is



We have the velocity of the transverse waves in stretched string as


And,

Therefore the relation between the two is,


Finally substituting this value at the frequency beat equation we have


Therefore the beats per second are 11.92Hz
Here is the correct answer of the given problem above.
Given that the basket has a mass of 5.5kg, the magnitude of the normal force if the basket is at rest on a ramp inclined above the horizontal is at 12 degrees. The solution is simple:
<span>Fn at rest = lmgl </span>
<span>= 5.5kg (9.80N/kg)
=</span><span> mgCos12degrees
Hope this answer helps. </span>
The sun has orbited along time so when they ask theses questions I give you the right answer I think lol