Module 10

Question 1

It defines a kind of motion that shows repetition and definite pattern.

Answer 1

Harmonic motion

Question 2

It is the branch of science dealing with the study, analysis, and application of sound.

Answer 2

Acoustics

Question 3

It is a disturbance of molecules within a given substance.

Answer 3

Sound

Question 4

It is a medium where sound propagates without carrying over the matter where it moves. It do not only carry sounds but also different things such as electrical signals, light, and so on.

Answer 4

Wave

Question 5

It is a wave that results from interaction with matter.

Answer 5

mechanical wave

Question 6

What are the three types of mechanical waves?

Answer 6

Surface wave, longitudinal wave, and transverse wave.

Question 7

It is a wave that propagates along with the interface between different media. This mechanical wave creates a disturbance on the matter’s surface. The wave generated carries over the energy of the source of the disturbance.

Answer 7

surface wave

Question 8

It is a wave whose vibrations travel along the direction of the wave. Thus, if a wave is moving to the right, the vibrations also move to the right. This wave creates areas of compression where loose molecules clump together during transmission at certain intervals. This wave travels fastest in a solid, which becomes nonexistent in a vacuum, where no molecules can support the wave.

Answer 8

longitudinal wave

Question 9

It is a wave whose vibrations travel perpendicularly from the wave’s direction. It travels at certain intervals and is usually drawn like a sine curve. It travels the fastest in a vacuum, which becomes nonexistent in a solid, where the matter only absorbs the energy carried by the wave.

Answer 9

transverse wave

Question 10

What are the parts of a transverse wave?

Answer 10

Crest, trough, amplitude, wavelength, and frequency

Question 11

It is the highest point of the transverse wave.

Answer 11

Crest

Question 12

It is the lowest point of the transverse wave.

Answer 12

Trough

Question 13

It is the distance between the peak or trough of the wave and the equilibrium position.

Answer 13

Amplitude

Question 14

It is the distance between two (2) crests or troughs. Its symbol is the Greek letter lambda (𝜆).

Answer 14

wavelength

Question 15

It is the number of waves per measured time.

Answer 15

frequency

Question 16

It is the densest point of the longitudinal wave.

Answer 16

compression

Question 17

It is the loosest point of the longitudinal wave.

Answer 17

rarefaction

Question 18

A longitudinal wave’s _______ is the distance between two (2) compressions or
rarefactions.

Answer 18

wavelength

Question 19

It is the measure of how fast a wave propagates from the source traveling outwards.

Answer 19

Wave speed (𝑣)

Question 20

It is a phenomenon that occurs when an object with a natural frequency receives a forced vibration at a similar frequency.

Answer 20

Resonance

Question 21

It is any cord that is pulled taut, and its center is allowed to vibrate when plucked, strummed, or any other action that will cause it to vibrate.

Answer 21

string

Question 22

It is a structure that allows frequencies to resonate along the length of the pipe before going out, with flutes as an example.

Answer 22

open-ended tube

Question 23

A wave that behaves similarly to a vibrating string.

Answer 23

open-end air column

Question 24

It is a system that limits the frequency by forcing it to move to the other end, like how we create sound by blowing from an empty coke bottle.

Answer 24

close-end air column

Question 25

The lowest possible frequency for a standing wave is known as its _____ _____, which can be determined by the presence of nodes and antinodes.

Answer 25

fundamental frequency

Question 26

Every wave, whether it’s from sunlight or earthquakes, carries energy.

Answer 26

Wave Energy

Question 27

This is the rate at which energy is transferred by the wave.

Answer 27

Wave Power

Question 28

This is the amount of power that passes through a unit area of the wave’s medium.

Answer 28

Wave Intensity

Question 29

Occurs when two waves simultaneously interact with each other or when both waves happen at the same time.

Answer 29

Wave Superposition

Question 30

The formation of a reflected pulse is similar to the overlap of two (2) pulses traveling in the opposite direction. These converging pulses create a superposition, where the pulses overlap and pass each other; the total displacement of the string is the algebraic sum of the displacements at that point in the individual pulses.

Answer 30

The Pulse Behavior

Question 31

It occurs if waves are in sequence. When two waves overlap in phase, their crests combine to create a larger wave with an amplitude equal to the sum of the two waves.

Answer 31

Constructive Interference

Question 32

It occurs if waves counter each other. When two waves overlap out of phase, their crests and troughs align, and they cancel each other out or form a smaller wave. The resultant wave no longer disturbs the medium.

Answer 32

Destructive interference

Question 33

A wave that behaves differently. It can have superposition, but its fixed ends dictate its behavior.

Answer 33

Sinusoidal Behavior

Question 34

It is the section in which the string never moves.

Answer 34

Nodes

Question 35

It is the section where the string moves and where the amplitude is at its greatest.

Answer 35

antinode

Question 36

These are waves that appear stationary. They are also capable of both constructive and destructive interferences; the only downside is that they cannot transfer energy.

Answer 36

Standing waves

Question 37

Standing wave with a definite length L and both ends fixed, like in guitars, violins, and pianos.

Answer 37

Normal Mode

Question 38

It is produced by the compression and expansion of the medium. It is also generated from the vibrations of an object.

Answer 38

Sound

Question 39

It always travels outward in all directions from the source, with an amplitude that depends on the direction and distance from the source.

Answer 39

Sound waves 

Question 40

A measure of the size of the variation in air pressure caused by the sound wave.

Answer 40

Pressure Amplitude

Question 41

It is the change in frequency of a wave caused by the movement of the source relative to the observer. As the source approaches, the frequency increases; as it moves away, the frequency decreases.

Answer 41

Doppler shift

Question 42

It is any substance that characterizes flow, i.e., any substance that has no rigid structure is amorphous and conforms to the shape of the receptacle it is in.

Answer 42

Fluid

Question 43

It is defined as the amount of mass m per unit volume V of a substance. It can be computed by simply dividing the mass of the object by its volume. Its SI unit is kg/m3.

Answer 43

Density

Question 44

A fluid's_____ _____ is the ratio of a fluid's density compared to a standard fluid density.

Answer 44

specific gravity (𝑔𝑠𝑝)

Question 45

It is a measure of how much force is applied over a given area. It is the magnitude of the force on a surface per unit area. The force is perpendicular to the surface area.

Answer 45

Pressure (P)

Question 46

It is the measure of how it resists flowing. Physically, it is the ratio of shearing stress (𝜏) to the velocity gradient in a fluid. Its unit is pascal-second (Pa ⋅ s), but it is rarely used in the scientific community, preferring the Poise (P) and the dyne-s/ cm2 over it

Answer 46

Viscosity

Question 47

The unit Poise is named in honor of the French physiologist _____ _____

Answer 47

Jean Poiseuille

Question 48

Fluids exist only in two (2) states:

Answer 48

static and dynamic

Question 49

A fluid is considered to be _____ if there is no change in a fluid contained in a receptacle. This means that the density is constant and uniform throughout its volume. This is one (1) of the characteristics of an ideal fluid.

Answer 49

static

Question 50

A principle that states that pressure applied to a fluid in a closed container is transmitted equally to every point of the fluid and the walls of the container.

Answer 50

Pascal's Principle

Question 51

A principle that states that states that any object completely or partially submerged in fluid experiences an upward buoyant force equal in magnitude to the weight of the fluid displaced by the object.

Answer 51

Archimedes’ Principle

Question 52

A fluid is considered to be ____ if there is motion involved or if there are changes in the system. The motion of real fluids is very complicated and not yet fully understood.

Answer 52

dynamic

Question 53

The following are the four (4) assumptions about ideal fluids:

Answer 53

1. Incompressible flow 2. Laminar flow 3. Newtonian flow 4. Irrotational flow

Question 54

The similar assumption to fluids at rest; the density is constant and uniform.

Answer 54

Incompressible flow

Question 55

The flow of fluids is said to be steady or laminar if the velocity of moving fluid at a fixed point does not change.

Answer 55

Laminar flow

Question 56

The viscosity of a fluid dictates the rate of flow of a fluid. If one dips their fingers in a Newtonian fluid, there is absolutely nothing to slow one down.

Answer 56

Newtonian flow

Question 57

A British scientist who was also 3rd Baron Rayleigh, noted that a boat moving through a Newtonian fluid will never come to a stop even if all engines were shut down.

Answer 57

John William Strutt

Question 58

A type of flow where fluid particles do not rotate about their center of mass, even though they may move in curved paths.

Answer 58

Irrotational flow

Question 59

It states that if the speed of a fluid element increases as the element travels along a horizontal streamline, the pressure of the fluid must decrease, and conversely.

Answer 59

Bernoulli’ Principle

Question 60

_____ _____ formulated an equation that relates the pressure of a moving fluid to the fluid density, speed, and altitude.

Answer 60

Daniel Bernoulli

Question 61

It states that the speed of a liquid flowing under the force of gravity out of an opening in a tank is proportional jointly to the square root of the opening's vertical location. Simply put, if some liquid flows at an opening located near the base of a tank, its flow velocity is equal to the flow velocity of a liquid flowing out from the opening located at the top of the tank.

Answer 61

Torricelli’ Principle

Question 62

He is an Italian physicist that once studied the principles of how the flow distance of fluids decreases as the height increases while maintaining the same flow velocity.

Answer 62

Evangelista Torricelli

Question 63

What are the limitations of Bernoulli’s Equation?

Answer 63

1. The velocity of a given fluid flowing in a system is maximum when near the center of the pipe it flows in, in which the velocity gradually decreases as the fluid comes near the pipe’s walls. Thus, in every equation and problem solving, the fluid’s mean velocity is used due to the inconsistency of the fluid’s velocity within the system. 2. There are still external forces acting on the fluid, which affects the flow rate of the fluid. Thus, in using the Bernoulli equation, the scenario must neglect such outside forces, which should be taken into account in reality. So, if energy is transferred in the flowing system, it will be taken into consideration. 3. In the case of turbulent flows, some kinetic energy is converted into heat energy. In a viscous (similar to thick) flow, some of the energy is lost due to shear forces. Therefore, all such losses must not be taken into account whenever using this equation. 4. Should the fluid flows within a curved path, the energy due to centripetal motion must be considered.

Question 64

What are the assumptions of Bernoulli’s Equation?

Answer 64

1. The fluid must be ideal and incompressible, meaning it can act on any scenario. 2. The flow must be steady, meaning no disruptions. 3. The flow must be one-dimensional. 4. The fluid velocity must be uniform over the section and must be equal to its mean velocity. 5. The only forces allowed to interact with the system are gravity and pressure.