P1.10 Liquid pressure and Upthrust

• Which 3 factors determine the pressure exerted by a liquid?

  (for example the pressure exerted on a submerged ball by the surrounding by surrounding water)

  1. The depth. At greater depth, more pressure is exerted.
  2. The density or the liquid. More dense liquids exert greater pressure.
  3. The gravitational field strength, which is 9.8 N/m on earth.
• What is the formula for the pressure exerted by a liquid?

  Pressure (p) = height (h) x density ($p$) x gravitational field strength (g)
• What is upthrust?

  Upthrust is a force that pushes upwards on an object submerged in a fluid (liquids and gases).
• What determines whether an object in liquid will float or sink?

  It the weight of the object is greater than the upthrust from the water, it will sink.

  If the upthrust from the water is greater than the weight of the object, it will float.

  Another way to think about it is that if the object is more dense than water it will sink.
• What primarily causes the pressure acting on an object submerged in water?

  The surrounding water molecules colliding with the object
• What additional factor contributes to the pressure on an object as it goes deeper in water?

  The weight of the water above the object
• How does the pressure in a liquid change with depth?

  Pressure increases as the depth increases
• What determines the pressure in a liquid?

  The density of the liquid and the gravitational field strength
• What is the equation for pressure in a liquid?

  Pressure = height of liquid column × density × gravitational field strength
• What is up thrust in the context of submerged objects?

  It is the resultant upward force acting on a submerged object due to pressure differences
• How does the density of an object affect its ability to float?

  If the object's density is greater than the liquid's density, it sinks; if less, it floats
• What are the factors that affect pressure in a liquid?

  • Depth of the liquid
  • Density of the liquid
  • Gravitational field strength