Physics Topic 3 Materials Fluids Quiz

1. What is the definition of Density?

Density = Weight/Volume = W/V

Density = Mass x Volume = m x V

Density = Volume/Mass = V/m

Density = Mass/Volumep=m/V

Density is defined as the mass of an object divided by its volume. The correct formula is density = mass/volume = p = m/V.

Explanation

Density is defined as the mass of an object divided by its volume. The correct formula is density = mass/volume = p = m/V.

2. What is the pressure at the base of the column and the volume of the column? As a result, what is the value of P?

Pressure at base = V p / g A, Volume of the column = A / h, Hence P = V h

Pressure at base = V / p g, Volume of the column = A h, Hence P = V / h

Pressure at base = A p g, Volume of the column = V h, Hence P = A / V

Pressure at base= V p g/AV= A hP=h p g

The correct answer defines the relationship between pressure, volume, area, and height of the column in terms of P, h, g, and A. The incorrect answers provide alternative formulas that mix up the variables, leading to incorrect calculations.

Explanation

The correct answer defines the relationship between pressure, volume, area, and height of the column in terms of P, h, g, and A. The incorrect answers provide alternative formulas that mix up the variables, leading to incorrect calculations.

3. What is Archimedes' Principle?

The volume of a partially submerged object will always be greater than the volume of fluid it displaces.

The weight of an object wholly or partially immersed in a fluid is the difference between the weight of the fluid displaced and the weight of the object.

A body fully or partially submerged in water will displace half of its weight in water.

The upthrust is equal to the weight of the displaced fluid.

Archimedes' Principle states that the upthrust or buoyant force acting on an object that is immersed in a fluid is equal to the weight of the fluid that the object displaces. This principle helps explain why objects float or sink in fluids.

Explanation

Archimedes' Principle states that the upthrust or buoyant force acting on an object that is immersed in a fluid is equal to the weight of the fluid that the object displaces. This principle helps explain why objects float or sink in fluids.

4. What is Upthrust equal to?

U = mA Upthrust = mass x acceleration

U = p V gUpthrust = density x volume x g

U = F/W Upthrust = Force/Weight

U = Fd Upthrust = Force x distance

Upthrust is a buoyant force experienced by an object immersed in a fluid. It is calculated as the product of density, volume, and acceleration due to gravity, as shown in the correct answer formula.

Explanation

Upthrust is a buoyant force experienced by an object immersed in a fluid. It is calculated as the product of density, volume, and acceleration due to gravity, as shown in the correct answer formula.

5. What makes an object float? And why do boats have Plimsoll lines?

Objects float when they are lighter than water.

An object will float in a fluid if the upthrust is equal to its weight.Plimsoll lines indicate how far the boat will sink or float, due to salt concentration.

Objects float because of their shape and size.

Plimsoll lines are decorative features on boats.

Plimsoll lines help boats navigate through rough waters only.

An object floats when the upthrust is equal to its weight, regardless of its size or shape. Plimsoll lines are critical for safety, indicating how much weight a boat can carry based on the surrounding water's salt concentration.

Explanation

An object floats when the upthrust is equal to its weight, regardless of its size or shape. Plimsoll lines are critical for safety, indicating how much weight a boat can carry based on the surrounding water's salt concentration.

6. What is laminar flow?

Turbulent flow:- Fluid flows smoothly and in parallel lines without any disturbances or cross currents.

Plug flow:- Flow behavior where the entire fluid moves at the same velocity from one end of the pipe to the other without mixing.

Vortex flow:- Fluid flow characterized by a rotating motion creating vortices or whirlpools.

Laminar flow:- Layers of fluid continue in lines at a constant velocity- the lines do not mix- the layers slide over each other- the streamlines stay attached

Laminar flow is known for its smooth movement of fluid in parallel layers without mixing, resulting in orderly streamlines. It is important to distinguish laminar flow from turbulent flow, vortex flow, and plug flow for a clear understanding.

Explanation

Laminar flow is known for its smooth movement of fluid in parallel layers without mixing, resulting in orderly streamlines. It is important to distinguish laminar flow from turbulent flow, vortex flow, and plug flow for a clear understanding.

7. Describe turbulent flow?

Boundary layer flow:- Flow close to a surface- Velocity gradient from maximum at the surface to zero at the interface.

Turbulent flow:- The flow lines are unstable- Layers mix- The layers form swirls/ Eddies- The velocity is not constant- Flow lines become detached

Laminar flow:- Flow lines are parallel- Layers do not mix- Velocity is constant- Flow is smooth.

Plug flow:- Flow moves in a straight line- No mixing between layers- Occurs in long pipes.

Turbulent flow is characterized by unstable flow lines, mixing of layers, formation of swirls/eddies, non-constant velocity, and detached flow lines. Laminar flow, plug flow, and boundary layer flow have distinct characteristics different from turbulent flow.

Explanation

Turbulent flow is characterized by unstable flow lines, mixing of layers, formation of swirls/eddies, non-constant velocity, and detached flow lines. Laminar flow, plug flow, and boundary layer flow have distinct characteristics different from turbulent flow.

8. What is viscosity?

Viscosity is the color of a liquid.

Viscosity is the temperature of a liquid.

Viscosity is the smell of a liquid.

Viscosity of a liquid refers to its stickiness and thus its resistance to flow.

Viscosity is a measure of a fluid's resistance to flowing. It is not related to the color, temperature, or smell of a liquid.

Explanation

Viscosity is a measure of a fluid's resistance to flowing. It is not related to the color, temperature, or smell of a liquid.

9. What is Stokes' Law?

F = 6 x Pi x Eta x Radius x Velocity

G = 2 x Pi x Eta x Radius x Velocity.

F = 4 x Pi x Eta x Radius x Velocity.

F = 6 x Pi x Eta x Radius x Acceleration.

Stokes' Law relates to the drag force experienced by a spherical object moving through a fluid. The correct formula is F = 6 x Pi x Eta x Radius x Velocity, where F is the drag force, Eta is the dynamic viscosity of the fluid, Radius is the radius of the sphere, and Velocity is the velocity of the sphere.

Explanation

Stokes' Law relates to the drag force experienced by a spherical object moving through a fluid. The correct formula is F = 6 x Pi x Eta x Radius x Velocity, where F is the drag force, Eta is the dynamic viscosity of the fluid, Radius is the radius of the sphere, and Velocity is the velocity of the sphere.

10. What is the formula for the coefficient of viscosity?

Coefficient of viscosity = Ps^2 - Pf^2 + 5gr/3V

Coefficient of viscosity = Ps + Pf + 2gr^2/9V

Coefficient of viscosity = 2(Ps - Pf)gr^2/9V

Coefficient of viscosity = 4(Ps - Pf)gr^2/9V

The correct formula for the coefficient of viscosity is derived from the formula for Stokes' law in fluid dynamics.

Explanation

The correct formula for the coefficient of viscosity is derived from the formula for Stokes' law in fluid dynamics.

11. What does the free-fall of a sphere falling in fluid look like?

Look at picture

It moves in a perfect straight line.

It spins rapidly in circles.

It moves in a zig-zag pattern.

The correct answer suggests referring to a picture for a visual representation, rather than describing the motion of the sphere.

Explanation

The correct answer suggests referring to a picture for a visual representation, rather than describing the motion of the sphere.

12. What factors can cause variations in viscosity?

Pressure

TemperatureThixotropy

Chemical composition

Humidity

Viscosity of a substance can be affected by various factors such as temperature and thixotropy, which is the temporary decrease in viscosity of a material under shear and then gradual recovery of viscosity over time.

Explanation

Viscosity of a substance can be affected by various factors such as temperature and thixotropy, which is the temporary decrease in viscosity of a material under shear and then gradual recovery of viscosity over time.