Flashcards
Pressure
Cards in this deck (16)
- 1Define Pressure. What are the units of pressure?The amount of force acting on a unit of area.
N/cm2 (newton,cm,squared) - 2Give 3 formulas from the triangle of pressure.force/area =pressure
pressure x area=force
force/pressure= area - 3The pressure due to a force depends on 2 factors, name them.1.Pressure increases when the force increases.
2.Pressure increases when the area that the force is acting on decreases - 4How does pressure vary with depth in liquids?Give examples of this.The value of pressure will increase as you go deeper below the surface of a liquid.
* A dam wall is thicker at the base then at the top. - 5What is atmospheric pressure?The pressure due to the WEIGHT of the gases PUSHING down on the earth.
- 6How does atmospheric pressure vary with height?*It decreases with height above sea level.
- 7Where is pressure greatest- at the top of a mountain or at sea level. Why?At sea level.
There is more pressure ,because there is more gases pushing down on you. - 8How do you measure pressure? Name 2 types.A barometer is used.
1)Anaeroid barometer
2)Mercury barometer - 9What are isobars?Lines on a weather chart that joins areas with equal atmospheric pressure
- 10How do you measure altitude?An altimeter is used.
- 11When the pressure is: a)high b)low what will the weather be like?a)clear,settled,dry
b)wet,windy,dull - 12What does it mean when isobars are a)close together b)far aparta)the winds will be strong
b)the winds will be light - 13What is the normal atmospheric pressure?1014 hPa
hPa-hectopascal=unit of A.P - 14What are applications of pressure?1)water supply systems-the greater the height of the reservoir the greater the pressure.
2)Hydraulics-Liquids used to create large pressures in machinery. - 15Why is low atmospheric pressure associated with bad weather?Low A.P means that it is easier for water to evaporate into the air because the 'blanket' of A.P pressing down on the water is lighter.
- 16Increased pressure, increased....... Decreased pressure, decreased......increased...boiling point
decreased....boiling point