Pressure

Cards (6)

  • Pressure is the force per unit area: Pressure (Pa) =\Pr essure\ \left(Pa\right)\ = Force (N)Area (m2)\ \frac{Force\ \left(N\right)}{Area\ \left(m^2\right)} or P =P\ = FA\ \frac{F}{A}
  • The unit of pressure is Pascals: Pa =Pa\ = Nm2\ \frac{N}{m^2}
  • In liquids: Pressure (Pa) =\Pr essure\ \left(Pa\right)\ = Density (kgm3) x Gravity (ms2) x Height (m)\ Density\ \left(\frac{kg}{m^3}\right)\ x\ Gravity\ \left(\frac{m}{s^2}\right)\ x\ Height\ \left(m\right)
  • As the depth of a fluid increases, the pressure caused by the whole liquid increases.
  • The manometer:
    1. Measures the pressure difference between a liquid and the atmosphere
    2. The height difference shows the excess pressure in addition to the atmospheric pressure
  • Barometer:
    • Tube with vacuum at the top and mercury filling the rest
    • Pressure of the air pushes down on reservoir, forcing mercury up the tube
    • Measure height of the mercury
    • ~760mm of mercury is 1 atm