P11 Flashcards
What is meant by pressure
Pressure is the force normal to a surface / area of the surface
Force / Area
What is the unit of pressure
Pascal ( Pa ), which is equal to 1 N/m squared
How does the pressure along a horizontal line act
It will flow until the pressure along the same horizontal level is constant
What does the pressure in liquid depend on
The greater the density of a liquid, the greater the pressure in the liquid
How to calculate the pressure caused by liquid column
Height x density x gravity ( 10 )
Why does the atmosphere exert pressure
Air molecules collide with surfaces and create pressure on them
How and why does atmospheric pressure change with altitude
Atmospheric pressure decreases with higher altitude because there is less air above a given altitude than there is at a lower altitude, density of an atmosphere decreases with an increasing altitude
How to calculate the force on a flat object due to a pressure difference
Pressure difference x area of the flat surface
What is meant by an upthrust on the object in a fluid
It is an upward force on the object due to the fluid, it is caused by the pressure of this fluid
What does the pressure of a fluid depend on
The density of the fluid and depth of the fluid at that point
How do you explain with an object in a fluid floats or sinks
An object sinks if it’s a weight is greater thatn the upthrust on it when fully emersed
