Physics_Fluid Mechanics Overview

True or False: A boat floats because the buoyant force is less than the weight of the boat.

• True

• False

• A boat floats because the buoyant force is equal to the weight of the boat.

• A boat floats because the buoyant force is greater than the weight of the boat.

What is the principle of flotation?

• A floating object displaces a weight of fluid equal to its own weight.

• A floating object sinks if it weighs more than the fluid it displaces.

• An object will float if it is less dense than the fluid.

• Flotation occurs only in liquids, not in gases.

How does salinity affect the buoyancy of an object in water?

• Increased salinity decreases the density of water, making it harder for objects to float.

• Increased salinity increases the density of water, which can increase the buoyant force on an object, making it more likely to float.

• Salinity has no effect on the buoyancy of objects in water.

• Increased salinity causes objects to sink regardless of their density.

What is the difference between absolute pressure and gauge pressure?

• Absolute pressure is the pressure relative to atmospheric pressure, while gauge pressure is the total pressure exerted on a system.

• Absolute pressure is the total pressure exerted on a system, including atmospheric pressure, while gauge pressure is the pressure relative to atmospheric pressure.

• Absolute pressure is always higher than gauge pressure, regardless of the conditions.

• Gauge pressure is measured in pascals, while absolute pressure is measured in atmospheres.

What does Archimedes' Principle state?

• An object in a fluid will sink if it is denser than the fluid.

• When an object is immersed in a fluid, it experiences an upward force equal to the weight of the fluid it displaces.

• An object will float if it is less dense than the fluid.

• The pressure in a fluid increases with depth.

How does pressure change with depth in a fluid?

• Pressure decreases with depth.

• Pressure remains constant with depth.

• Pressure increases with depth.

• Pressure fluctuates with depth.

Explain Archimedes’ principle with an example.

• A boat floats on water because it displaces water, and the upward buoyant force is greater than the weight of the boat.

• A rock sinks in water because it is heavier than the water it displaces.

• A balloon rises in the air because it is filled with helium, which is lighter than air.

• A cup overflows when filled with water because the water cannot be displaced.

True or False: The shape of an object affects its buoyancy.

• True

• False

• It depends on the material

• Only in water

What happens if an object displaces more water than its own weight?

• It sinks.

• It floats.

• It remains submerged.

• It evaporates.

Why do submarines sink and rise in the ocean?

• Submarines control their buoyancy by adjusting the amount of water in their ballast tanks.

• Submarines use propellers to push water downwards.

• Submarines are designed to be heavier than water at all times.

• Submarines rely on external forces like waves to move up and down.