Easy
Define viscosity.
Viscosity is the measure of a fluid's resistance to flow.
Describe how temperature affects the viscosity of a liquid.
Viscosity generally decreases as temperature increases.
A block of wood has a density of 0.6 g/cm³ and is placed in water. Describe what will happen to the block.
The wood will float because its density is less than water’s.
According to Pascal's Law, how does pressure behave in an enclosed fluid?
Pressure applied to an enclosed fluid is transmitted equally in all directions.
How does temperature affect the density of a substance? Use the PMOM to justify your explanation.
Higher temperatures cause particles to spread apart, decreasing density.
What is the formula for density?
Density = Mass / Volume.
How does the viscosity of a liquid differ from the viscosity of a gas as more heat is applied?
Liquid viscosity decreases with heat, while gas viscosity increases.
Why are solids considered incompressible compared to liquids and gases?
Particles in solids are packed closely together and resist compression.
Today’s valves can control not only the flow, but also 4 other factors. Name 2 of them.
The rate, the volume, the pressure or the direction
In a hydraulic system, what is the advantage of using different-sized pistons?
A smaller piston creates high pressure that can be transmitted to a larger piston to lift heavy loads.
What is the formula for calculating pressure?
Pressure = Force / Area.
How does the concept of flow rate relate to viscosity?
Higher viscosity means a lower flow rate.
Why can a helium balloon be compressed while a water balloon cannot? Use the PMOM to explain.
Helium particles are far apart and compressible; water particles are closely packed and incompressible.
Explain Archimedes' Principle.
An object in a fluid experiences an upward force equal to the weight of the fluid it displaces.
How does the solubility of nitrogen in a diver's body change as they ascend to the surface?
Solubility decreases as pressure decreases, causing nitrogen to form bubbles if ascent is too quick.
What is the primary function of a pump in a fluid system?
To move fluids through a system by creating pressure.
What is the Plimsoll line on the side of a boat used for?
It indicates the safe loading limit of a ship based on water conditions.
What happens to the pressure at greater depths in a fluid?
Pressure increases with depth.
Using the Particle Model of Matter (PMOM), explain why heating a liquid decreases its viscosity.
Heating increases particle movement, reducing resistance and allowing particles to flow more easily.
What role do surfactants play in the cleaning process of detergents?
The surfactant encapsulates the fat & dirt molecules in the water, removing them from the fabric.
If the area of contact is decreased while the force remains constant, what happens to the pressure?
Pressure increases.
You have a liquid with a mass of 45g and a volume of 15mL. Calculate its density.
Density = 3 g/mL.
Why do balloons pop when punctured with a tack, but not when multiple tacks are used?
A single tack applies greater force to a small area, creating higher pressure.
Imagine you are conducting an experiment to measure the viscosity of two different liquids. Describe the procedure you would use.
Measure the time it takes for each liquid to flow through a narrow tube; compare flow rates.
Why is it important for SCUBA divers to ascend slowly?
To prevent nitrogen bubbles from forming in the blood, reducing the risk of decompression sickness.