P11 Pressure Flashcards
What are the two equation to work out pressure?
Pressure = Force / Area
Pressure = Density x gravity (9.8) x height
What is the unit of pressure?
N/m^2 or Pascals
What is upthrust?
The upward force that a fluid exerts on the body floating on it
What happens when an object is lowered into water?
It displaces some of the water.
What is Archimedes’ Principle?
The more the object is lowered into the water, the greater the amount of water displaced
What is the density of water?
1000 kg/m^3
Why does the pressure in liquid increase as depth increases?
The number of particles above that point increases, the weight of these particles adds to the pressure felt at that point.
Why does atmospheric pressure decrease with height?
As the altitude increases, the atmosphere gets less dense so there are fewer air molecules that are able to collide with the surface
The greater the density of the liquid…
the greater the pressure in the liquid.
What is the equation linking pressure, denstiy and graviational field strength?
Pressure = height x density x gravitational field strength
What is the scientific unit for density?
Kg/m^3
How do air molecules create pressure?
By colliding with surfaces.
What is the upthrust of an object in a fluid?
An upward force on the object due to the fluid.
What is the upthrust of an object in a fluid caused by?
The pressure of the fluid
