P11 - Forces and Pressure Flashcards
D. Pressure?
force per unit area
Unit of pressure?
pascal
1 Pascal = …
1N/m2
E. Pressure of a liquid column?
p =h x ρ x g ( pressure = height x liquid density x gravitational field strength )
Liquid flows until…
the pressure along the same horizontal level is constant
As the density of the liquid increases….
the pressure increase
What creates air pressure?
Air molecules collide with surfaces and create pressure on them
The density of the atmosphere decreases with increasing…
altitude
Atmospheric pressure decreases with…
why?
higher altitude
because there is less air above a given altitude than there is at a lower altitude
E. Pressure at sea level?
p = h x ρ x g (pressure = height x density x gravity)
E. Force on a flat object due to pressure difference?
= pressure difference x area of flat surface
D. Upthrust?
the upwards force that acts on a body partly or completely submerged in a fluid, due to pressure of the fluid
The pressure at a point in a fluid depends on…
- the density of the fluid
- the depth of the fluid at that point
An object sinks if…
its weight is greater then the upthrust
An object floats if…
its weight is equal to the upthrust
