I would say that the answer would be MASS.
Answer:
The answer is "
"
Explanation:
For point a:
Energy balance equation:


From the above equation:

because the rate of air entering the tank that is
constant.
Since the tank was initially empty and the inlet is constant hence,
Interpolate the enthalpy between
. The surrounding air
temperature:

Substituting the value from ideal gas:

Follow the ideal gas table.
The
and between temperature
Interpolate

Substitute values from the table.
For point b:
Consider the ideal gas equation. therefore, p is pressure, V is the volume, m is mass of gas.
(M is the molar mass of the gas that is
and R is gas constant), and T is the temperature.


For point c:
Entropy is given by the following formula:

Answer:
The tangential velocity of a rotating object is:
v = r*w
where r is the radius, and w is the angular velocity.
w = 2*pi*f
where f is the frequency.
We know that the record plater does 11 revolutions in 20 seconds, then it does:
11 rev/20s = 0.55 rev/s = f
then we have:
w = 2*pi*0.55 s^-1 = 2*3.14*0.55 s^-1 = 3.454 s^-1
The radius of a record player is really variable, it is around 10 inches, so i will use r = 10in, which is the rotating part of the record player.
then the tangential velocity is:
v = 10in*3.454 s^-1 = 34.54 in/s