The correct answer is Option C) Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
As the coefficient of absorption would define the energy present in the reflected wave, the material C has the highest percentage of absorption i.e. 62% and would be best suitable to make a sound proof room.
Following statements are true
(i) The leather jacket has a lower tendency to attract electrons than sweater.
When the sweater and the leather jacket are in contact with each other, the leather jacket loses electrons and thus becomes positively charged. the electrons are gained by the sweater and it becomes negatively charges.
The opposite charge attract. so the sweater ( negatively charged) will attract protons ( positively charged) . The leather jacket ( positively charged) will attract the electrons ( negatively charged).
Complete Question
The complete question is shown on the first uploaded image
Answer:
The velocity is 
in positive x -direction
The speed is 
Explanation:
From the question we are told that
The distance from the house to truck is D = 20 m
The distance traveled back to retrieve wind-blown hat is d = 15
The distance from the wind-blown hat position too the truck is k = 20 m
The total time taken is t = 75 s
Generally when calculating the displacement the Justin's backward movement to collect his wind - blown hat is taken as negative
Generally Justin's displacement is mathematically represented as
=> 
Generally the average velocity is mathematically represented as
=> 
=>
Generally the distance covered by Justin is mathematically represented as
=> 
=> 
Generally Justin's average speed over a 75 s period is mathematically represented as
=> 
=>
<span>Depends on the precision you're working to.
proton mass ~ 1.00728 amu
neutron mass ~ 1.00866 amu
electron mass ~ electron mass = 0.000549 amu
Binding mass is:
mass of constituents - mass of atom
Eg for nitrogen:
(7*1.00728)-(7*1.00866)-(7*0.000549)
-14.003074 = 0.11235amu
Binding energy is:
E=mc^2 where c is the speed of light. Nuclear physics is usually done in MeV[1] where 1 amu is about 931.5MeV/c^2. So:
0.11235 * 931.5 = 104.6MeV
Binding energy per nucleon is total energy divided by number of nucleons. 104.6/14 = 7.47MeV
This is probably about right; it sounds like the right size!
Do the same thing for D/E/F and recheck using your numbers & you shouldn't go far wrong :)
1 - have you done this? MeV is Mega electron Volts, where one electronVolt (or eV) is the change in potential energy by moving one electron up a 1 volt potential. ie energy = charge * potential, so 1eV is about 1.6x10^-19J (the same number as the charge of an electron but in Joules).
It's a measure of energy, but by E=mc^2 you can swap between energy and mass using the c^2 factor. Most nuclear physicists report mass in units of MeV/c^2 - so you know that its rest mass energy is that number in MeV.</span>
