Answer:
a = 0
Explanation:
The velocity of a sound wave in a straight line is 660 mph. The wave is moving with a constant velocity. It means that the change in velocity is equal to 0.
We know that acceleration of an object is equal to the change in velocity divided by time taken. But here the change in velocity is 0. As a result the acceleration of the sound wave is 0.
Kirchhoff's circuit laws are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits. They were first described in 1845 by German physicist Gustav Kirchhoff. This generalized the work of Georg Ohm and preceded the work of Maxwell.
Complete Question
A parallel plate capacitor creates a uniform electric field of 5 x 10^4 N/C and its plates are separated by 2 x 10^{-3}'m. A proton is placed at rest next to the positive plate and then released and moves toward the negative plate. When the proton arrives at the negative plate, what is its speed?
Answer:

Explanation:
From the question we are told that:
Electric field 
Distance 
At negative plate
Generally the equation for Velocity is mathematically given by

Therefore




It's Endorphins. That's a pain killer produced by the brain.
Answer: C. Metals are found on the left side of the periodic table.
Explanation:
The periodic table contains vertical columns called as groups and horizontal rows called as periods.
Period 2 contains 8 elements which are lithium, beryllium , boron , carbon, nitrogen, oxygen , fluorine and neon. Only Lithium and beryllium are metals.
Group 18 contains all the noble gases which are all non metals.
Metals are the elements which loose electrons easily and form positive ions. Non-metals are the elements which can gain electrons easily and form negative ions.
Metals are present on left side of the periodic table and as we move to right side of the periodic table , the metallic character decreases and thus non metals are found on the right side of the periodic table.