Upthrust and atmospheric pressure

• What is the concept of upthrust in fluids?

  It is the upward force exerted by fluids.
• How does fluid pressure explain why potatoes sink and apples float?

  Fluid pressure affects buoyancy based on density.
• What happens to an object submerged in a fluid?

  • Pressure of fluid exerts force in all directions.
  • The upward force is called upthrust.
• What happens to pressure in fluids with depth?

  Pressure increases with depth in fluids.
• What is the relationship between the forces acting on an object submerged in a fluid?

  The force on the bottom is greater than on top.
• What does the upward force on an object submerged in a fluid cause?

  It causes a resultant upward force known as upthrust.
• How is upthrust related to the weight of displaced fluid?

  Upthrust equals the weight of displaced fluid.
• What determines whether an object will float or sink in a fluid?

  • If upthrust equals weight, it floats.
  • If weight is greater than upthrust, it sinks.
• What happens if an object's weight is equal to the upthrust?

  The object will float in the fluid.
• What occurs when an object's weight is greater than the upthrust?

  The object will sink in the fluid.
• What does it mean if an object is less dense than the fluid?

  The object will float in the fluid.
• What happens to an object that is denser than the fluid?

  The object will sink in the fluid.
• How do submarines adjust their buoyancy?

  • They fill tanks with water to increase weight.
  • They use compressed air to decrease weight.
• What is the weight of an apple compared to the upthrust?

  The weight of an apple is less than upthrust.
• What is the weight of a potato compared to the upthrust?

  The weight of a potato is greater than upthrust.
• What is the significance of density in floating and sinking?

  • Density determines buoyancy.
  • Less dense objects float; denser objects sink.
• What happens to an object that is less dense than the fluid?

  The object will float in the fluid.
• How do large tanks affect the buoyancy of submarines?

  They increase the weight to sink the submarine.
• What is the role of compressed air in submarines?

  It reduces weight to allow floating.
• What is the relationship between weight and upthrust for floating objects?

  • Weight equals upthrust for floating.
  • If weight exceeds upthrust, the object sinks.
• What is the purpose of filling large tanks with water in this context?

  To increase the weight of submarines
• How does filling tanks with compressed air affect the weight of submarines?

  It reduces the weight of submarines
• What happens to atmospheric pressure with height?

  It decreases with height
• What surrounds the Earth according to the study material?

  A layer of air
• What is created on a surface by colliding air molecules?

  Atmospheric pressure
• How does altitude affect atmospheric pressure?

  Higher altitude leads to lower pressure
• What is the relationship between altitude and air density?

  Air density decreases with increasing altitude
• What happens to air molecules as altitude increases?

  Fewer air molecules are present
• What is the effect of altitude on the density of the atmosphere?

  The atmosphere gets less dense
• How does the weight of air above a surface affect pressure?

  More weight increases the pressure
• What is the significance of the relationship between atmospheric pressure and altitude?

  It helps understand weather patterns
• What is the formula for density?

  Density = mass/volume
• Why does a wooden object float in water?

  Because its density is less than water
• What does it mean if an object has a density of $700 \text{ kg/m}^3$?


  It is less dense than water
• What is the density of water?

  1000 kg/m³
• What happens to the pressure of a gas when its density changes?

  Pressure changes with density
• How do atmospheric pressure and liquid pressure compare?

  They are similar but differ in density
• What is the effect of altitude on the density of air molecules?

  Density decreases as altitude increases
• What is the relationship between pressure and altitude?

  Pressure decreases with increasing altitude
• What does a decrease in atmospheric pressure indicate?

  It indicates an increase in altitude