Hi guys so i have some questions if you can help:-
1.When is force=weight?
2. Can the rule P= dhg be applied on all problems involving pressure or does it have to be pressure at a certain point inside A LIQUID because my school book has put this law only under the title pressure at a certain point
inside a liquid?
Thanks guys!
1.When is force=weight?
2. Can the rule P= dhg be applied on all problems involving pressure or does it have to be pressure at a certain point inside A LIQUID because my school book has put this law only under the title pressure at a certain point
inside a liquid?
Thanks guys!
-
The force on a stationary object due to a gravitational field is the weight of the object.
I'm guessing this is about pressure, see below. Pressure varies with depth, so the formula only applies to a given depth. It applies to liquid or to gases, although for gases the formula is not too useful as density varies with depth.
Pfluid = ρgh
Pfluid is pressure in Pa or N/m²
ρ is the density of the fluid in kg/m³
density of water at 20C = 0.998 g/cm³ = 998 kg/m³
density of seawater = 1.025 g/cm³ = 1025 kg/m³
g is the acceleration of gravity 9.8 m/s²
h is the height of the fluid above the object in m
I'm guessing this is about pressure, see below. Pressure varies with depth, so the formula only applies to a given depth. It applies to liquid or to gases, although for gases the formula is not too useful as density varies with depth.
Pfluid = ρgh
Pfluid is pressure in Pa or N/m²
ρ is the density of the fluid in kg/m³
density of water at 20C = 0.998 g/cm³ = 998 kg/m³
density of seawater = 1.025 g/cm³ = 1025 kg/m³
g is the acceleration of gravity 9.8 m/s²
h is the height of the fluid above the object in m
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1) Weight IS a Force
Weight = mass * gravity = mass * acceleration of gravity = mass * acceleration = MA = Force
2) Pressure = density * depth * acceleration of gravity = dhg
Is true for all points in a liquid. When your book says, "at a certain point" it means any point with the same density, depth and acceleration.
Weight = mass * gravity = mass * acceleration of gravity = mass * acceleration = MA = Force
2) Pressure = density * depth * acceleration of gravity = dhg
Is true for all points in a liquid. When your book says, "at a certain point" it means any point with the same density, depth and acceleration.