What is the pressure of the water in pascals at the bottom og a lake which is 5 meters deep?
water density, rho, is about 1,000 kg/m^3
the mass of a column of water one square meter in cross section and h meters high is therefore:
mass = rho * 1 * h
= 1,000 h kilograms
the weight of that mass is mg =
1,000 * 9.81 * h Newtons
the pressure is that force over the one square meter where Newtons/m^2 is called Pascals
9,810 h Pascals
Now you should really distinguish between "gage" pressure and "absolute" pressure. Gage pressure is just what we said here:
9,810 * 5 Pascals
if you want absolute pressure you must at one atmosphere to that which is about an additional 10^5 Pascals
To calculate the pressure of the water at the bottom of a lake, you can use the formula:
Pressure = Density × Gravity × Height
In this case, the pressure will be acting on the water at the bottom of the lake, so the height 'h' would be the depth of the lake, which is given as 5 meters.
The density of water is approximately 1000 kg/m^3, and the acceleration due to gravity is approximately 9.8 m/s^2.
Plugging these values into the formula, we get:
Pressure = 1000 kg/m^3 × 9.8 m/s^2 × 5 m
Calculating this equation will give you the pressure in pascals (Pa).