Hazard is a possible source of danger
Answer:
The sound intensity is reduced by a factor of 1995.26
Explanation:
When comparing two sound intensities, the intensity level is measured in the unit of decibel or dB. The intensity of the threshold of hearing for a human being is 10^−12 W/m^2
. When the intensity level is zero, it means that the sound intensity is the same as the threshold of hearing.
The reduced sound intensity level is given as 33 dB, so
10 log (I/Io) = - 33
I : intensity of the sound
Io ( =
10^−12 W/m^2): threshold of hearing
So, the intensity ratio is
I/Io = 10^-3.3
= 5.01 x 10^-4
1/ 5.01 x 10^-4 = 1995.26
Answer:
0.0625kg/s
0.9031kW
Explanation:
At state 1, enthalpy and entropy are determined from table R-134a.
P1 = 400kpa
h1 = 255.55kj
S1 = 0.92691
h2 = 270kj/kg
Enthalpy at states 3 and 4 can be gotten from the pressure and state with data from a-12
h3 = h4 = 95.48kj/kg
1.)
The mass flow rate
= QL/h1 - h4
= 10/255.55-95.48
= 10/160.07
= 0.0625kg/s
2.)
The power requirement
= 0.0625(270-255.55)
= 0.9031 kW
