2 Basic Acoustic Flashcards
(43 cards)
Why is the basics of the physics of Biomedical Acoustics important?
It is the backbone for an engineer in biomedical acoustics providing essential theoretical aspects needed for understanding clinical rehabilitation or diagnostics.
What are the basic properties of moving bodies in the context of Basic Acoustics Physics?
Displacement (s), velocity (v), and acceleration (a) with equations v = v0 + at, v2 = v0^2 + 2as, and s = v0t + 1/2at^2.
What is the unit of measurement for weight (m*g) and force?
Weight is measured in Newtons (N) and force is also measured in Newtons (N).
What is the formula for force?
F = ma where F is force, m is mass, and a is acceleration.
What is the formula for kinetic energy (Ekin)?
Ekin = 1/2 mv^2 where m is mass and v is velocity.
What is the formula for potential energy (Epot)?
Epot = mgh where m is mass, g is the acceleration due to gravity, and h is height.
What are the three elements of an electrical circuit?
The Voltage (U), the current (I), and the resistance (R).
What is Ohm’s Law?
R = V/I where R is resistance, V is voltage, and I is current.
What is Young’s Modulus?
Young’s Modulus is a mechanical property that measures the tensile stiffness of a solid material quantifying the relationship between tensile stress and axial strain.
What does young’s modulus change to in 3D (since sound is used in 3D)?
Bulk modulus.
Compression force per unit area / decrease volume per unit area
What is the unit of pressure in acoustics?
Pressure is measured in Pascals (Pa).
What is the formula for pressure (P)?
P = F/A where F is force and A is surface area.
What is the equation for the adiabatic process in acoustics?
An adiabatic process occurs without transferring heat or mass between the system and its surroundings.
Define vibration in the context of motion.
A vibration is when a point of motion always returns to the starting point with the motion being random in any direction.
What is oscillation?
Oscillation is when a point goes in one direction, returns to the starting point, and then goes in the opposite direction, repeating the process.
What is a sine wave?
A sine wave is a mathematical curve that describes a smooth periodic oscillation and is the graph of the function sine.
What variables are associated with sinusoidal motion?
Amplitude (A), frequency (f), angular frequency (2πf), and phase.
How are different sine waves perceived by humans?
The sine wave of less frequency is perceived as softer than the sine wave of high frequency.
What is the solution for the differential equation for sine waves?
The solution for the differential equation for sine waves is of the form: y(t) = A sin(ωt + φ) where A is the amplitude, ω is the angular frequency, and φ is the phase constant.
What is underdamping?
Underdamping refers to a condition in an oscillatory system when the damping equals 0. The system will oscillate forever without any change in amplitude.
What is normal damping?
Normal damping refers to the condition in a vibrating system where the damping force is proportional to the velocity of the vibrating object resulting in a gradual reduction of the amplitude of oscillation over time without causing a significant delay or overshoot in the response.
What is overdamping?
Overdamping is a phenomenon in mechanical and electrical systems where the damping force is so strong that it prevents the system from oscillating, allowing it to return to equilibrium slowly without overshooting.
What does the quality factor (Q factor) represent?
The Q factor is a dimensionless parameter that describes how underdamped an oscillator or resonator is, defined as the ratio of a resonator’s center (peak) frequency to its bandwidth (the frequency at 1/sqrt(2) of the peak value).
What is a longitudinal wave?
Longitudinal waves are waves in which the particle displacement is in the same direction as or the opposite direction to the direction of wave propagation (parallel).
Sound in air is a typical example of a longitudinal wave
