Floating or sinking

• What should you be able to calculate by the end of this video?

  Pressure due to a column of liquid
• What happens when holes are made in the side of a water container?

  Water squirts out, further from the bottom hole
• Why does water from the bottom hole squirt out further?

  Because it is at a higher pressure
• What is the equation to calculate the pressure of a column of liquid?

  Pressure = height × density × gravitational strength
• What values are provided in the exam for pressure calculations?

  Density and gravitational field strength
• If a freshwater lake has a depth of 8 meters, what is the pressure at the bottom?

  78,400 Pascals
• How does pressure change with depth in a liquid?

  Pressure increases with depth
• What causes the pressure of a liquid to increase?

  Greater weight of liquid acting downwards
• What is upthrust in relation to floating objects?

  Resultant force acting upwards on an object
• What must upthrust equal for an object to float?

  Object's weight
• What happens if upthrust is less than the object's weight?

  The object sinks
• What occurs when an object is lowered into water?

  The water level lowers due to displacement
• What is the relationship between the force acting on an object and the weight of water displaced?

  They are equal
• What does an object need to do to float?

  Displace its own weight of water
• What happens when an object is less dense than water?

  It floats high in the water
• What must an object with the same density as water do to float?

  Displace its own volume of water
• What occurs when an object is more dense than water?

  It sinks because it can't displace enough water
• Where can you find questions on pressure in liquids?

  In the vision workbook
• What factors influence whether an object floats or sinks?

  Density of the object and water displacement
• How does the density of an object affect its ability to float?

  Less dense objects float, denser sink