Photon energy is directly proportional to the frequency of electromagnetic radiation.
(That would also mean that it's inversely proportional to the wavelength.)
So the photon energy increases as you scan the chart of visible colors
moving from the red end of the rainbow to the blue end.
At the bottom of the tank :
P = ρgH
P = (1000 kg/m³)(10 m/s²)(1 m)
P = 10000 N/m²
F = P • A
F = (10000 N/m²)(1 m²)
F = 10000 N
At the side of the tank :
Pav = ½ρgH
Pav = ½(1000 kg/m³)(10 m/s²)(1 m)
Pav = 5000 N/m²
F = P • A
F = (5000 N/m²)(1 m²)
F = 5000 N
