Answer:
Frequency = 658 Hz
Explanation:
The third harmonics of A is,

The second harmonics of E is,

The difference in the two frequencies is,
delta_f = 1320 Hz - 1318 Hz = 2 Hz
The beat frequency between the third harmonic of A and the second harmonic of E is,
delta_f = 

We have calculate the frequency of the E string when she hears four beats per second, then
delat_f = 4 Hz


Hope this helps!
<h3><u>Answer;</u></h3>
<em>Electrons </em>
<h3><u>Explanation;</u></h3>
- <em><u>Thomson contributed to the model of an atom by discovery of </u></em><em><u>electrons </u></em><em><u>and thus proving the existence of sub-atomic particles in an atom. </u></em>
- <u><em>Thomson used cathode ray tube, and demonstrated that cathode rays were negatively charged.</em></u> According to his model normally known as the plum pudding in which he stated that an atom is composed of electrons as subatomic particles that are surrounded by positive charges to balance the electrons.
Answer:
The outside of a neuron has more sodium ions while at resting state. When a electrical signal is going to pass through, the sodium channels open up first and the positive sodium ions rush inward making the inner side more positive. This is called action potential.
There is layer of fatty substances called as Myelin Sheath over the course of axons. It helps the electrical signal to be transmitted with a fast pace and efficiently over the course.