Liquid Pressure & Upthrust

Cards (20)

  • What are we going to calculate in this video?
    Pressure in a liquid and floating objects
  • 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 formula 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 moving from 20 meters to 90 meters?
    Subtract pressure at 20m from 90m
  • What is the change in pressure when moving from 20 meters to 90 meters?
    686,000 pascals
  • What is up thrust in relation to submerged objects?
    Upward force exerted by surrounding water
  • 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 object's 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 object's weight?
    The object floats
  • How can we determine if an object will float without calculating up thrust and weight?
    By comparing densities of the object and liquid
  • What happens to a dense object like a rock in water?
    It sinks
  • What happens to a less dense object like an apple in water?
    It floats
  • What factors determine the pressure in a liquid?
    • Depth of the liquid
    • Density of the liquid
    • Gravitational field strength
  • What are the conditions for an object to float or sink?
    • If up thrust > weight, it floats
    • If weight > up thrust, it sinks
  • What is the relationship between density and buoyancy?
    • Denser objects sink
    • Less dense objects float