Answer:
Double blind experiment
Explanation:
It is an experimental method , which helps to avoid any impartiality and any error due to biasing .
The experiment give rise to very accurate results , which is very important for any experiment .
Hence , the new director Margaret , need to design a set of double - blind experiments.
Explanation : Explain each characteristic of sound waves.
Intensity : the intensity of the sound wave is understand as the power carry by sound wave per unit area in the direction perpendicular to that area.
Loudness : loudness is the quality of the loud and soft of the sound wave.
Frequency : Human normal hear sound frequency between 20 Hz to kHz.
Pitch : Pitch is the quality of low and high of sound wave . pitch relates to the frequency of the slowest vibration in the sound wave for simple sound.
m x h x 9.8 m/s squared
70 kg x 3 m x 9.8 m/s squared= 2058 Joules
Answer:
ΔS total ≥ 0 (ΔS total = 0 if the process is carried out reversibly in the surroundings)
Explanation:
Assuming that the entropy change in the aluminium bar is due to heat exchange with the surroundings ( the lake) , then the entropy change of the aluminium bar is, according to the second law of thermodynamics, :
ΔS al ≥ ∫dQ/T
if the heat transfer is carried out reversibly
ΔS al =∫dQ/T
in the surroundings
ΔS surr ≥ -∫dQ/T = -ΔS al → ΔS surr ≥ -ΔS al = - (-1238 J/K) = 1238 J/K
the total entropy change will be
ΔS total = ΔS al + ΔS surr
ΔS total ≥ ΔS al + (-ΔS al) =
ΔS total ≥ 0
the total entropy change will be ΔS total = 0 if the process is carried out reversibly in the surroundings
