Fluids

• What is meant by the term 'fluid'?

  A liquid or a gas.
• In any fluid, at what angle do the forces due to pressure act on a given surface?

  At right angles (normal to) the surface.
• State the equation used to calculate pressure. Give appropriate units.

  Pressure (Pa) = Force (N) / Area (m^2)

  P = F/A
• Why does atmospheric pressure vary with the height above the Earth's surface?

  The number of air molecules decreases the higher you go. This means that the weight of air above a point decreases, meaning the pressure also decreases.
• True or false? The pressure in a fluid is determined by the fluid and the atmospheric pressure.

  True.
• What direction does pressure act in?

  All directions.