At what depth in the lake is the pressure 400 kPa.

Given:

P = 400 kPa – pressure in the lake at a certain depth.

ro = 1000 kg / m3 (kilogram per cubic meter) – water density.

It is required to determine h (meter) – depth.

Let’s convert the units of measurement of pressure to the SI system:

P = 400 kPa = 400 * 10 ^ 3 = 400,000 Pascal.

Then, to determine the depth, you must use the following formula:

P = ro * g * h (where g = 10 Newton / kilogram is an approximate value).

From here we find that:

h = P / (ro * g);

h = 400000 / (1000 * 10) = 400000/10000 = 40 meters.

Answer: the water pressure will be 400 kPa at a depth of 40 meters.