D. physical property
the bonds between molecules of mercury are breaking so it's physical and it's not changing the chemical composition of the substance
Data:

n (Wave node)
V (Wave belly)
L (Wave length)
<span>The number of bells is equal to the number of the harmonic emitted by the string.
</span>

Wire 2 → 2º Harmonic → n = 2







Wire 1 → 1º Harmonic or Fundamental rope → n = 1



If, We have:
V = 42L
Soon:



Answer:
<span>The fundamental frequency of the string:
</span>
21 Hz
Answer:
20m/second
Explanation:
The reason the answer is 20m/second is because to find the speed of the ball in this question you have to divide the distance over the time giving you the result of 20m/second
If one of two interacting charges is doubled, the force between the charges will double.
Explanation:
The force between two charges is given by Coulomb's law

K=constant= 9 x 10⁹ N m²/C²
q1= charge on first particle
q2= charge on second particle
r= distance between the two charges
Now if the first charge is doubled,
we get 
F'= 2 F
Thus the force gets doubled.
The answer is C. elastic potential energy