Liquid Pressure and Upthrust

• What primarily causes pressure on an object submerged in water?

  Surrounding water molecules colliding with it
• What happens to pressure as an object moves deeper in water?

  Pressure increases due to more water above
• What determines the pressure in a liquid?

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

  Pressure = height × density × gravitational strength
• If the height of the liquid column is 20 meters, density is 1000 kg/m³, and gravitational strength is 9.8 m/s², what is the pressure?

  196,000 pascals
• What is the pressure at a depth of 90 meters with the same density and gravitational strength?

  882,000 pascals
• How do you calculate the change in pressure when diving from 20 meters to 90 meters?

  Subtract pressure at 20m from 90m
• What is the change in pressure when diving from 20 meters to 90 meters?

  686,000 pascals
• What is up thrust in relation to submerged objects?

  Up thrust is the upward force on the object
• Why does a submerged box experience a larger upward force at the bottom?

  Because the bottom is deeper than the top
• What determines whether an object floats or sinks?

  Comparison of up thrust and weight
• What happens if the weight of an object is larger than the up thrust?

  The object sinks
• What happens if the up thrust is larger than the weight?

  The object floats
• How can we determine if an object will float or sink without calculating forces?

  By comparing densities of object and liquid
• What happens if an object is denser than the liquid?

  The object sinks
• What happens if an object is less dense than the liquid?

  The object floats
• What factors determine the pressure in a liquid?

  • Depth of the liquid
  • Density of the liquid
  • Gravitational field strength
• How does up thrust affect floating and sinking?

  • Up thrust is the upward force
  • If up thrust > weight, object floats
  • If weight > up thrust, object sinks
• What is the relationship between density and buoyancy?

  • Denser objects sink
  • Less dense objects float