Flashcards
unit 2 (c14, c15, c16)
Cards in this deck (105)
- 1frequency equiv.f= 1/T
- 2Period equiv.T= 1/f
- 3ang. freq related to freq.w=2*pi*f
- 4freq. related to ang freq.f= w/(2*pi)
- 5Spring force eqnFx= - kx
(spring force)= -(spring const.)*(displacement) - 6eqn. for accel. of object on springax= (Fx)/(m) = (-k*x)/(m)
- 7ang. freq. related to spring const.w= (k/m)^(1/2)
- 8True/False: Energy is conserved in SHMTrue
- 9True/False: In angular SHM, f and ww are related to the moment of inertia (i) and Ktrue
- 10eqn. to relate w, K, and I for angular SHMw = (K/I)^(1/2)
- 11eqn. to relate f, K, and I for angular SHMf = (1/(2*pi))*(K/I)^(1/2)
- 12eqn. for the period of a simple pendulumT = 2*pi*(L/g)^(1/2)
- 13Torque of a simple pendulum eqn.T=mgLsin(theta)
- 14moment of inertia of a simple pendulum eqn.I=mL^2
- 15what is moment of inertia?a measure of how resistant an object is to changes in its rotational motion
- 16what is frequency?Frequency describes the number of waves that pass a fixed place in a given amount of time
- 17what is angular frequency?the angular displacement of any wave element per unit of time or the rate of change of the waveform phase
- 18what is period?the time it takes for the vibrating object to make one cycle or oscillation and return to its original position
- 19what is amplitude?the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position
- 20what is spring constant?It is a measure of the spring's stiffness.
- 21what is spring force?the spring force always acts so as to restore mass back toward its equilibrium position
- 22True/False: The spring force is NOT a restoring forcefalse
- 23what is angular momentum?the quantity of rotation of a body, which is the product of its moment of inertia and its angular velocity
- 24what is the equation for ang. momentumL = mvr
- 25what is a simple pendulum?A simple pendulum consists of a mass m hanging from a string of length L and fixed at a pivot point P.
- 26what is a physical pendulum?A physical pendulum refers to an object which oscillates back and forth, in contrast to the rather idealized simple pendulum where all the mass is concentrated in a single point
- 27describe the difference between a simple and physical penduluma simple pendulum is a point mass and a string. A physical pendulum is any object whose oscillations are similar to those of the simple pendulum, but cannot be modeled as a point mass on a string, and the mass distribution must be included into the equation of motion.
- 28write the eqn. for the period of a physical pendulum in terms of angular frequencyT = (2*pi)/w
- 29write the eqn. for the period of a physical pendulum in terms of mass, gravity, inertia, and heightT = 2*pi *((I)/(mgh))^(1/2)
- 30write the eqn. for the frequency of a physical pendulum in terms of mass, gravity, inertia, and heightf = (2*pi)^(-1)*((mgh)/(I))^(1/2)
- 31write the eqn. for the angular frequency of a simple pendulumw = (g/L)^(1/2)
- 32write the eqn. for the frequency of a simple pendulum(2*pi)^(-1)*(g/L)^(1/2)
- 33explain conservation of energy equation in SHM using WORDSmechanical energy = kinetic energy + potential energy
- 34write the conservation of energy eqn. for SHMEtot = 0.5*m*(Vx)^2+0.5*K*x^2
OR
Etot = 0.5*K*A^2
(0.5)*(spring const.)*(amplitude of oscillation) - 35write the equation used to find the position of an object in SHMx(t) = A*cos(w*t+phi)
where phi is the phase shift - 36what is phase shift?the difference in the position of a wave at a given point in time compared to the position of the same wave at the same point in time in another location
- 37what is a dampened oscillation?A damped oscillation refers to an oscillation that degrades over a specific period of time
- 38write the equation for angular displacement as a function of time
- 39what is the displacement of an oscillator with little damping?
- 40what is the equation for the angular frequency of a dampened oscillator?
- 41True/False: The larger the dampening constant, the faster the amplitude will decreaseTrue
- 42what is a sinusoidal wave?A sine wave, sinusoidal wave, or sinusoid is a periodic wave whose waveform is the trigonometric sine function. As a physical motion over time, this is simple harmonic motion, the one-dimensional projection of uniform circular motion.
- 43describe a forced oscillationWhen a sinusoidally varying driving force is added to a damped harmonic oscillator, the resulting motion is called a forced oscillation or driven oscillation
- 44what is resonance?The amplitude is a function of the driving frequency wd and reaches a peak at a driving frequency close to the natural frequency of the system. This behavior is called resonance.
- 45define a waveA wave is any disturbance that propagates from one region to another
- 46what does a wave travel through?a medium
- 47what determines the wave speedthe type of wave and the properties of the medium
- 48What is the wavelength (λ)The wavelength λ is the distance over which the wave pattern repeats
- 49write the equation for the wave speed in respect to wavelength and frequencyv=λf
- 50what does a wave function do (y(x,t))?describes the displacements of individual particles of the medium
- 51what is a transverse wavea wave in which the vibrating element moves in a direction perpendicular to the direction of advance of the wave.
- 52describe the difference between a transverse and longitudinal wave
- 53what is a longitudinal wave?waves where the displacement of the medium is in the same direction as the direction of the travelling wave
- 54what is rarefractionthe reduction of an item's density, the opposite of compression.
- 55what is compression (in respect to a wave)a region in a longitudinal wave where the particles are closest together
- 56what type of wave has compression and rarefraction?longitudinal
- 57what determines the sped of a transverse waveThe tension and the mass per unit length (μ)
- 58what is the equation for the speed of a transverse wave
- 59give the wave equation for a sinusoidal wave traveling in the positive x-direction
- 60how do we express power for a sinusoidal mechanical wave?For a sinusoidal mechanical wave, the average power Pav is proportional to the square of the wave amplitude and the square of the frequency
- 61write the eqn for the power of a mechanical sinusoidal wave
- 62Describe intensity (I)Intensity is the quantity of energy the wave conveys per unit time across a surface of unit area, and it is also equivalent to the energy density multiplied by the wave speed. It is generally measured with units of watts per square meter
- 63True/False: Intensity decreases as distance from the source increasestrue
- 64The inverse square law for intensity states "The intensity is inversely proportional to the square of the distance from the observer to the source". Write this as an eqn.
- 65describe wave superpositionA wave reflects when it reaches a boundary of its medium. At any point where two or more waves overlap, the total displacement is the sum of the displacements of the individual waves (principle of superposition)
- 66write an eqn. to describe wave superposition
- 67describe a wave nodethe points that have no displacement from the equilibrium position (amplitude is minimum here)
- 68describe a wave antinodeAntinodes are points of maximum displacements (at crests and toughs) from the mean position
- 69what is a standing wavecombination of two waves moving in opposite directions, each having the same amplitude and frequency. The phenomenon is the result of interference
- 70what is wave interferenceWave interference is the phenomenon that occurs when two waves meet while traveling along the same medium. The interference of waves causes the medium to take on a shape that results from the net effect of the two individual waves upon the particles of the medium.
- 71what is the difference between constructive and destructive wave interferenceConstructive interference happens when two waves overlap in such a way that they combine to create a larger wave. Destructive interference happens when two waves overlap in such a way that they cancel each other out
- 72when can a standing wave occurConsider a string fixed on both ends. In general the waves reflected from both ends produce an interference pattern that is complex and confusing. But when the wavelength of the waves is just right, so that an integral number of half wavelengths fit into the length of the string, a standing wave forms
- 73describe the fundamental frequency of a mechanical wavethe lowest frequency of a periodic waveform
- 74how does frequency and normal-modes relateThe normal modes of a standing wave are all just multiples of the fundamental frequency. This means that sin(kL) must be equal to zero
- 75what is the wave number (k)the spatial frequency of a wave over a specific unit distance
- 76what is the eqn. to describe normal mode frequencies
- 77write the eqn. to find the fundamental frequency on a string fixed at both ends
- 78True/False: Increasing tension in a string increases the wave speed, as well as the frequencytrue
- 79what is sound?sound is a longitudinal wave in a medium
- 80what is the bulk modulus?Sometimes referred to as the incompressibility, the bulk modulus is a measure of the ability of a substance to withstand changes in volume when under compression on all sides
- 81write the eqn. for the bulk modulus
- 82What is youngs modulus?Young's modulus is a measure of the ability of a material to withstand changes in length when under lengthwise tension or compression. Sometimes referred to as the modulus of elasticity, Young's modulus is equal to the longitudinal stress divided by the strain.
- 83write the eqn. for youngs modulus
- 84what determines the speed of a sound wave in a fluidThe Bulk Modulus and the density
- 85what is pressure amplitude? (Pmax)Pressure amplitude is a measure of the size of the variation in air pressure caused by a sound wave
- 86write the eqn. for Pmax
- 87write the eqn. to solve for the wave speed in a fluid
- 88write the eqn. to solve for the wave speed in an ideal gas
- 89what is the gas constant (R)?defines energy per temperature. Equal to 8.3145 J/(mol*K)
- 90write the eqn. to find the speed of sound in a solid rod
- 91True/False: During compression, the Pmax is the highest
- 92True/False: The sound intensity (β) is a logarithmic scale of its intensity.True. It is measured relative to I naught which is equal to 10 ^-12 W/m^2 and expressed in decibals (dB)
- 93write the equation to solve for sound intensity
- 94write the eqn. for the normal mode frequencies for a pipe of length L that is open at both ends
- 95what is a stopped pipe?one that is open only at one end
- 96what is driving frequencyDriving frequency is the frequency of the driving force. The driving force is an external force applied to the oscillator
- 97write the eqn. for the normal mode frequencies of a stopped pipe
- 98True/False: The lowest resonant frequency is called the fundamental, while all higher resonant frequencies are called overtones. All resonant frequencies are multiples of the fundamental, and are called harmonicstrue
- 99what is a beat frequency?Beats are heard when two tones with slightly different frequencies fb and fa are sounded together. The beat frequency fbeat is the difference between fb and fa
- 100write the equation for the beat frequency
- 101what is the doppler effect?The Doppler effect for sound is the frequency shift that occurs when there is motion of a source of sound, a listener, or both, relative to the medium
- 102what two factors are related in the doppler effect?Frequency and speed of the soirce and listener
- 103write the eqn. for the doppler effect
- 104what is a shock waveA sound source moving with a speed vs greater than the speed of sound v creates a shock wave.
- 105write the equation to solve for the angle of a shock wave cone
