Answer:
a) 
b) 
Explanation:
The frequency of the
harmonic of a vibrating string of length <em>L, </em>linear density
under a tension <em>T</em> is given by the formula:

a) So for the <em>fundamental mode</em> (n=1) we have, substituting our values:

b) The <em>frequency difference</em> between successive modes is the fundamental frequency, since:

There are correlation and causation between the force of the finger and the movement of the books
Answer:
6.214g/cm³
Explanation:
The question is on density of a material
Density=mass/volume
Given, mass=87grams and volume= 14 cm³ density=?
Density=m/v 87/14 =6.214g/cm³
He feels a 10 N to the left force moves. Yes ,he moves.